This is one of those cases where MS contradicts itself, BoL says in one place that the limit is 256 and in another place that there it's limited only be available resources. That makes it a fun question.

http://msdn.microsoft.com/en-us/library/ms177634.aspx says there's a limit of 256.

http://msdn.microsoft.com/en-us/library/ms143432.aspx says "Limited only by available resources".

And when I went to click on 256 I somehow clicked on 32. Looks like I'm as careless as MS is!