Unexpected Windows nastiness

[David Glasgow]

Sorry for the vague subject line for this post, but I can't really  
put it in a nutshell.

I have got so used to building stuff on OS X and then just tweaking  
for Windows, I am completely thrown by this problem.  I am using  
Studio 2.7.4 on a MacBook with XP running under parallels for Windows  
testing.

I have a card which allows a user to select a folder which contains  
JPG images.  The filenames of these images are displayed in a number  
of fields in different ways, reflecting membership of groups which  
are specified by the name.  So ADF01.jpg, ADF02.jpg, ADF03.jpg etc.  
are all exemplars of the 'ADF category. There can be any number of  
categories, and the scripts work out how many and which image belongs  
to which category.  It sounds a bit complicated, but it isn't  
really.  Images can be viewed independently, or along with other  
members of the same category.

Images can be previewed by clicking on the filename, and then an  
order can be generated for something like a slideshow, using  
randomisation combined with conditions.

Anyway, it all works tickety boo in IDE and standalone using OS X.

In Win XP the filenames load and fields are populated as expected.   
Attempting to use any control, or indeed clicking anywhere on the  
card causes all the fields bar one disappear behind (?) a dark grey  
colour.  The single visible field and all obscured controls are  
unresponsive.  Clicking generally causes the 'program not responding'  
thingy to be thrown by the OS.  Not doing anything seems to have no  
effect, except the fans slowly crank up to full speed.

I have rebuilt the standalone, with the same effect.

I have tried searching archives for something like this, but  
struggled to identify any relevant terms.

Does any of this ring any bells?

David Glasgow