Ok, I've just ran my code using the debugger and stepped through it and I didnt get the same error - in fact it executed the code where the invalid scope error was generated. This is going to sound ridiculous, but if I step through it slowly, then it works ok, but if I execute without the debugger or step through it rapidly I get this error. Also noticed that the variables in the debugger are VERY slow to update while doing this. I'm not making this up ;-(