Title gets corrupted when opening a substack

[Tiemo Hollmann TB]

Hello,

I have a really wired phenomenon at one of my beta testers, Win XP.

Opening my mainstack, it has his title icon and title text, just normal.
When opening a substack (with toplevel) the title of the mainstack gets
completely corrupted. The title of the maintack shows only special chars, as
if it wouldn't find the font or language anymore.

In the stack properties\text of all of my stacks I have choosen no font, the
property is empty. Which font is choosen? Standard Rev font? Is it a godd
idea, not to choose a special font? But nevertheless, what font I have
choosen,  why does it only happens after opening a substack and why does it
only happens at one of ten PCs?

Has anybody seen this behaviour or has any idea, what is going on there?

Any hint appreciated

Tiemo