AutoIT errors

[MK-2]

I have a few tools that i had in au3 format on my memory stick from my old school.
ive just installed autoit and scite on the new machine, tried running one of the au3 scripts and it threw up some errors. i can run the already compiled exe so i decompiled that, try to run it and get errors (yet the exe runs!).
it is coming up with things like:
ERROR: _GUICtrlTreeViewExpand(): undefined function.
yet i have #include <guitreeview.au3> at the top and that is the only other place it is referenced.
what could be going on? i mean if i've included the guitreeview.au3 surely it should work?

[MK-2]

nevermind, sorted. didn't realise there was a new version of autoit out that didn't like the old scripts.