Procedure has already been executed [PB 11.5]

I have been having a big issue.

I am using SQL Server 2005 and PowerBuilder 11.5

I have added a call to a procedure (lets say proc1) in my PB app which contains a cursor that calls another procedure (lets say proc2). Proc2 is an intense procedure I use often during the everyday operations of the application. It contains Begin Tran sections.

After Proc1 is being executed, the first time I get to write to the database I get a mysterious "Procedure has already been executed".

The first thing that crossed my mind was that a TRAN has been left uncommitted.

But I did DBCC OPENTRAN and SELECT @@TRANCOUNT during several stages of the operation which, to my disappointment, returned 0. So no open TRAN exists.

Have u guys got a clue of what to look? This thing is making me crazy...