We have a kiosk like terminal, with a customized Ubuntu installation (customized only in that way, that only a few packages are installed, and the installation process is unattended). The thing is, on the terminal we tested, it works fine, but on the production one, grub hangs 2 seconds before it would actually boot the default kernel automatically.
The supposedly only change is, that on the test version we had, there is a hard disk, the production ones have flash drives. But that shouldn't be a problem, should it? If we hook up a keyboard, press ESC go into the grub menu, pick the default menu entry, it boots.
What could be a reason for this behaviour?
UPDATE: I think we found the bug. It seems there is a defect in the hardware. The clock doesn't work, so it seems the interrupt for the timer doesn't work as well, therefor the count down in grub doesn't work as well.