My apologies if this is in the wrong list....

I have created a simple database application with QT4.1 and MySql. It works well enough. My problem is that a couple of machines on the local network crash when I run it.

There are 6 main machines, 3 x XP, 2 x 2k, 1 x 98. They all work (as does my linux version). They all run the application from the server. They also work with the application installed locally.
We had a work experience student in this week and needed another machine for them to do some data entry. We built an older machine (removed from service <6 months ago due to HD failure) from scratch with a new install of 98.

On this older machine, the application I wrote would not run and would crash every time on the opening screen with a message indicating "qtgui4.dll caused an illegal instruction". We replaced the OS with 2000, no change. Tried 2 other old machines and still no change.

All the older machines are PII 200 MHz - 500 MHz CPUs with 64 Mb - 128 Mb RAM. All have latest VGA drivers and network drivers, etc. The existing 6 PCs that work are all new and are 1.8 GHz 256 Mb or better.

Is there a minimum requirement that the client PC must be before it will run a QT4 application? Is there some way to test resource requirements to find out what the minimum requirement is?

Any thoughts, suggestions or suggested reading would be appreciated.

Thank you, B1.