CScrollbar works on one pc but not on any others

I've written some code in c++ using a CScrollbar which scrolls a CWnd and treeview at the same time. This works perfectly find on my pc, but on other pc's in the office it has problems:

• it only scrolls up
• it allow开发者_Go百科s the user to scroll when they don't need to

I've tested this on Vista, XP, and Windows 7 and they all have the same result. My pc is running Windows XP.

My question is: do you know what might be the cause, and if not, how might I go about finding the cause? I don't really know where to start.

The only thing I can think of would be an uninitialised variable. Potentially in one of your SetScrollInfo calls. e.g Are you setting the fMask member of SCROLLINFO correctly?