I think it's related to the encryption/decryption of a column. At the moment this isn't supported. You can manipulate the queries after they're being generated, see the encryption/decryption thread of yours.
it's inserts which don't execute a function btw, updates do emit expressions (e.g. DbFunctionCalls) to the query. Inserts could obey this perhaps but it requires some changes in the DataAccessAdapter class and the SqlServer DQE (DynamicQueryEngine.cs, line 450-520). It might not be a big change, so we could look into altering the DQE a bit to make this work for you. (selects, updates already obey expressions set to fields. You need to set these expressions in an override to OnInitialized in a partial class of the entity).
But if you will use procs for CUD anyway, it's of course not worth the effort from our part. Should be look into this for you? (With expressions we mean DbFunctionCall instances for example.). If yes, please give us a full query in SQL (INSERT/UDPATE) how you want to use this, so I can see if it's possible to do (as the DbFunctionCall to emit in the INSERT's parameter list, is of course not getting info from the outside at query generation time. )
