STK1000/Hardware Known Issues
From AVRFreaks Wiki
Hi-Speed USB 2.0
STK1000 does not behave properly when using an USB cable longer than 1m at Hi-Speed USB2.0 (480 Mbit/s). The only supplied USB cable is tested to behave properly.
This issue was addressed with the rev C of STK1002 where USB connectors are moved from STK1000 to STK1002
PS2 voltages
No level conversion is done for the PS2 interface. This requires that keyboards and mice used with STK1000 are 3.3V compliant. This is not common for keyboards and mice.
Compact Flash hot insertion
STK1000 does not support hot insertion of Compact Flash cards. If a Compact Flash card is inserted when the processor is running then ringing on the data and address bus will lead to undefined behavior on the CPU.