Transaction Context In Use By Another Session Error

I have written a stored procedure that calls a C# class.  The sp is called by a trigger on table A.  The class has 2 methods.  Method 1 is the main call from the stored procedure.  Inside it, it sets a connection to the db.  Then it calls another private method which has it's own connection and returns a dataset so that I can close that connection by the end of the method.  When I execute the sp from within sql management studio, it runs just fine.  But when being called from the trigger, I get the "transaction context in use by another session error" error.  I read that I needed to wrap my 2nd connection in ...

using (new TransactionScope(TransactionScopeOption.Suppress))
{
  open conn here, do work, etc.
}

I've tried that and I still get the same error from the trigger.  Anyone know what else I can try?  Thanks.