I haven't had that problem.
First, you may want to check the rom and make sure it's not corrupt or improperly trimmed. If you have Rominator, you can validate it and make sure it's correct (assuming they have it in the database already -- they might not since it's new).
If you know the rom is OK, it may be having problems writing the SAV file for the first time. Try deleting the .sav file (if there is one) and see if it can re-create it. Otherwise, you may need to reformat your microSD.
-Bri