I\'m using NHibernate 3.1.0 and I\'m trying to extend the LINQ provider by using BaseHqlGeneratorForMethod and extending the DefaultLinqToHqlGeneratorsReg
Supposing the property Id of the class Project it's an Int32 try registering the corresponding Int32.ToString() method in your ToStringGenerator class.
...
public ToStringGenerator()
{
SupportedMethods = new[]
{
ReflectionHelper.GetMethodDefinition