Thanks, that's what I did prior to asking here hoping that someone using MM.NET encountered the problem before and may save me digging through all the possible solutions

>This is a very complex problem that is quite often shows up in ASP.NET application without clear indication of a cause. You can search at ASP.NET forums, you'll find many threads on this topic, but I don't think there is a clear work every time resolution.
>
>>Hi,
>>
>>using MM.NET 3.6 and VS2008.
>>
>>I'm not sure if this is a Mere Mortals thing or more general. I'm getting this error:
>>
>>

Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints. 
>>Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
>>
>>Exception Details: System.Data.ConstraintException: Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.
>>
>>Source Error: 
>>
>>Line 44:         public ReceiptEntity GetReceiptByPKForPrint(Guid receiptPK)
>>Line 45:         {
>>Line 46:             return this.GetEntity("ReceiptsSelectByPKForPrint",
>>Line 47:                 this.CreateParameter("@ReceiptPK", receiptPK));
>>Line 48:

>>
>>This is called when I want to print a receipt that has just been added to the database. It works when there is only one detail line in the receipt but when there are two lines I get this error.
>>
>>Any ideas as to what could be wrong here?