AbleCommerce Shopping Cart Software

I'm writing a some custom code for AbleCommerce, when I call the following from my code:

if (!Membership.ValidateUser(user, pass))
throw new SecurityTokenException("The user does not exist or was not validated with the given password.");

The following exception is thrown:
The INSERT statement conflicted with the FOREIGN KEY constraint "ac_Stores_ac_AuditEvents_FK1". The conflict occurred in database "f3256_ablecommerce", table "dbo.ac_Stores", column 'StoreId'.
The statement has been terminated.

Obviously, it some context isn't being set. Any ideas? Thanks.

Are you using the custom code inside AbleCommerce? If no then thats what causing the problem. AbleCommerce needs a context token that is initialized and it also takes into account the store license.