That'd be it.
Would be nice if that wasn't a limitation, but now I know what it is - I can work around it.
Thanks a lot.

Well I may as well post the project. Perhaps it's something another pair of eyes can spot. unexpected userdata is at line 32 of file controls.lua userdata accessed ok at line 12 of file physics.lua only place userdata set: line 66 & 77 of physics.lua (where did the function userdata come from?) ...

A test example is working. (darn it)
I'll look into it some more. Seems weird, I'm only setting userdata in one place and
the access to it from collision callbacks is working.

Thanks for a quick response. If it really has me stuck perhaps I'll post the project here.

Hi All I seem to be getting a function back from fixture:getUserData() in the callbacks of world:queryBoundingBox and world:rayCast - not the table I expect. (the only userData set anywhere in my code is a table, no functions) for the fixtures in beginContact, endContact etc it's working as expected...