KVM switch problems

I bought a cheap generic ('Ritmo') KVM switch and I am now regretting it...I can't use the keyboard properly prior to Windows booting up. On one PC, in the BIOS, there is a delay of about 3 seconds between pressing a button and the actual selection taking place. On the other PC, it's impossible to make any selections in the BIOS (the cursor constantly shifts from one section to another). However, once booted up both the mouse and keyboard work perfectly well in Win Xp and Vista.

Is this something which will still happen even if I buy a better KVM switch?

Thanks for any feedback...