Thread not starting on some machines

Hi guys,

I have a weird issue here. I'm writing an automated backup program that, well, performs automated backups of set folders to a set location. It has a GUI and a Windows service. The service has a timer (system.timer) that checks every 10 seconds whether a backup needs to be performed. If it does, it fires a method in a public static class to start the backup.

Now, this works fine on my PC, and on 2 other test PC's that I've used (Windows 7 32bit multicore, Windows 7 32bit singlecore, and XP 32bit multicore). But on some others, with the same specs, it doesn't work. The method isn't fired at all, which I *assume* to be a threading issue. I just don't know why. Are there any typical things I should look for?

Thanks in advance.