By definition if it's not a variable it's a constant and vice versa. So yes it's the issue.
It seems to be behaving as neither constant nor variable (despite the syntax), but as a keyword of the compiler. Which means it's up to the compiler to interpret that keyword appropriately. I'm suggesting that it would be appropriate for the compiler to interpret NULL in a useful way as a function parameter default.
Problem is, this is all but a new issue. It was already reported several times, and if it wasn't fixed before BlitzMax, chances are slim that it will be from now. Sadly.
Well, I'd have thought it to be the other way round. They're a small team and can't really be expected to divide their attention evenly across several products all the time. Once BlitzMAX is released for PC and initial bug reports are cleared, I would imagine they'll be better able to divert attention back to Blitz3D. Anyway...
This is an awful workaround, but seemed like good idea to post
Well, I don't think it's a bad work-around at all--especially it's brought to light a function I had no idea even existed: Handle() ...How long has that little beauty been around?! I just updated my help system with the latest, and that's still not in there! ...Aaaargh! :-S