when i ran the program, it threw an io exception that cant find dll "NHibernate, Version=3.0.0.4000, Culture=neutral, PublicKeyToken=aa95f207798dfdb4" or something like it. what i've done is just replace the nhibernate 3.0ga dll with the 3.1ga. so the fluent nhibernate really cant work with nhibernate 3.1? how should i make them work together? thanks for any help offered.