diff --git a/CHANGES.txt b/CHANGES.txt
index 85f8186a2..f646f3437 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,18 @@
 All bug numbers refer to the issue tracker at
 https://github.com/MiniZinc/libminizinc/issues
 
+Version 2.0.8
+=============
+
+Bug fixes:
+
+ - Fix incorrect negation of some reified comparisons.
+ - Make lb/ub functions work in more cases.
+ - Fix several bugs in the optimisation phase (could lead to incorrect
+   FlatZinc and crashes).
+ - Fix a problem with reverse mapper functions when the result of the reverse
+   mapper can be fixed to a constant.
+
 Version 2.0.7
 =============
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7e8cbaf2a..f78ef2473 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,7 +17,7 @@ project (libminizinc CXX)
 # The version number.
 set (libminizinc_VERSION_MAJOR 2)
 set (libminizinc_VERSION_MINOR 0)
-set (libminizinc_VERSION_PATCH 7)
+set (libminizinc_VERSION_PATCH 8)
 
 if (ADDITIONAL_DATE_STRING)
   set (libminizinc_VERSION_PATCH "${libminizinc_VERSION_PATCH}.${ADDITIONAL_DATE_STRING}")
diff --git a/lib/builtins.cpp b/lib/builtins.cpp
index 10e8dcde5..733233308 100644
--- a/lib/builtins.cpp
+++ b/lib/builtins.cpp
@@ -232,7 +232,7 @@ namespace MiniZinc {
     if (b.valid)
       return b.l;
     else
-      throw EvalError(env, e->loc(),"cannot determine bounds");
+      return -IntVal::infinity();
   }
   IntVal b_lb_varoptint(EnvI& env, Call* call) {
     ASTExprVec<Expression> args = call->args();
@@ -307,7 +307,7 @@ namespace MiniZinc {
     if (foundMin) {
       return array_lb;
     } else {
-      throw EvalError(env, e->loc(),"cannot determine lower bound");
+      return -IntVal::infinity();
     }
   }
 
@@ -316,7 +316,7 @@ namespace MiniZinc {
     if (b.valid)
       return b.u;
     else
-      throw EvalError(env, e->loc(),"cannot determine bounds");
+      return IntVal::infinity();
   }
   IntVal b_ub_varoptint(EnvI& env, Call* call) {
     ASTExprVec<Expression> args = call->args();
@@ -367,7 +367,7 @@ namespace MiniZinc {
     if (foundMax) {
       return array_ub;
     } else {
-      throw EvalError(env, e->loc(),"cannot determine upper bound");
+      return IntVal::infinity();
     }
   }
 
@@ -878,7 +878,7 @@ namespace MiniZinc {
         }
         break;
       default:
-        throw EvalError(env, ae->loc(),"invalid argument to ub");
+        throw EvalError(env, ae->loc(),"invalid argument to dom");
       }
     }
     if (al->v().size()==0)
diff --git a/lib/flatten.cpp b/lib/flatten.cpp
index 3e96ddf2d..5bd87e1ac 100644
--- a/lib/flatten.cpp
+++ b/lib/flatten.cpp
@@ -3411,8 +3411,9 @@ namespace MiniZinc {
           keepAlive->decl(constants().var_redef);
           ret = flat_exp(env, Ctx(), keepAlive, constants().var_true, constants().var_true);
           
-          env.reverseMappers.insert(ee.r()->cast<Id>(),revMap);
-          
+          if (ee.r()->isa<Id>()) {
+            env.reverseMappers.insert(ee.r()->cast<Id>(),revMap);
+          }
           break;
         }
         if ( (bo->op()==BOT_EQ ||  bo->op()==BOT_EQUIV) && (bo->lhs()==constants().absent || bo->rhs()==constants().absent) ) {
diff --git a/lib/optimize.cpp b/lib/optimize.cpp
index 5db868a2d..66c8f6519 100644
--- a/lib/optimize.cpp
+++ b/lib/optimize.cpp
@@ -590,7 +590,7 @@ namespace MiniZinc {
       if (bi->isa<ConstraintI>()) {
         c = bi->cast<ConstraintI>()->e()->dyn_cast<Call>();
       } else {
-        c = bi->cast<VarDeclI>()->e()->e()->dyn_cast<Call>();
+        c = Expression::dyn_cast<Call>(bi->cast<VarDeclI>()->e()->e());
       }
       if (c==NULL)
         continue;
@@ -910,7 +910,7 @@ namespace MiniZinc {
         Expression* arg = c->args()[0]->isa<Id>() ? c->args()[1] : c->args()[0];
         IntSetVal* domain = ident->decl()->ti()->domain() ? eval_intset(env,ident->decl()->ti()->domain()) : NULL;
         if (domain) {
-          BinOpType bot = c->args()[0]->isa<Id>() ? (is_true ? BOT_LQ : BOT_GQ) : (is_true ? BOT_GQ: BOT_LQ);
+          BinOpType bot = c->args()[0]->isa<Id>() ? (is_true ? BOT_LQ : BOT_GR) : (is_true ? BOT_GQ: BOT_LE);
           IntSetVal* newDomain = LinearTraits<IntLit>::limit_domain(bot, domain, eval_int(env,arg));
           ident->decl()->ti()->domain(new SetLit(Location().introduce(), newDomain));
           ident->decl()->ti()->setComputedDomain(false);
@@ -1257,6 +1257,7 @@ namespace MiniZinc {
                 env.flat()->fail(env);
                 vdi->e()->e(constants().boollit(isConjunction));
               }
+              toRemove.push_back(vdi);
             }
           } else {
             // not subsumed, nonfixed==1
@@ -1276,8 +1277,7 @@ namespace MiniZinc {
                 vd->e(constants().lit_true);
               }
             } else {
-              vdi->e()->e(id);
-              vardeclQueue.push_back(env.vo.idx.find(vdi->e()->id())->second);
+              remove = false;
             }
           }
           
diff --git a/lib/optimize_constraints.cpp b/lib/optimize_constraints.cpp
index 2d8191fe6..d78b932a3 100644
--- a/lib/optimize_constraints.cpp
+++ b/lib/optimize_constraints.cpp
@@ -145,11 +145,15 @@ namespace MiniZinc {
         al_c_new->type(Type::parint(1));
         ArrayLit* al_x_new = new ArrayLit(al_x->loc(),x_e);
         al_x_new->type(al_x->type());
-        c->args()[0] = al_c_new;
-        c->args()[1] = al_x_new;
-        if (d != 0) {
-          c->args()[2] = IntLit::a(eval_int(env,c->args()[2])-d);
-        }
+        
+        std::vector<Expression*> args(3);
+        args[0] = al_c_new;
+        args[1] = al_x_new;
+        args[2] = IntLit::a(eval_int(env,c->args()[2])-d);
+        Call* nc = new Call(Location(), c->id(), args);
+        nc->type(Type::varbool());
+        rewrite = nc;
+        return OptimizeRegistry::CS_REWRITE;
       }
       return OptimizeRegistry::CS_OK;
     }
@@ -187,9 +191,15 @@ namespace MiniZinc {
           al_c_new->type(Type::parint(1));
           ArrayLit* al_x_new = new ArrayLit(al_x->loc(),x_e);
           al_x_new->type(al_x->type());
-          c->args()[0] = al_c_new;
-          c->args()[1] = al_x_new;
-          c->args()[2] = IntLit::a(d);
+          
+          std::vector<Expression*> args(3);
+          args[0] = al_c_new;
+          args[1] = al_x_new;
+          args[2] = IntLit::a(d);
+          Call* nc = new Call(Location(),c->id(),args);
+          nc->type(c->type());
+          rewrite = nc;
+          return OptimizeRegistry::CS_REWRITE;
         }
       }
       return OptimizeRegistry::CS_OK;