certain keyboard keys not working after bootup

[fip04]

Hi,
i have a multimedia keyboard that is giving me some problems:
once i start my system and after booting up, some keys (especially the Backspace key, the 'N' key, the arrow keys) don't initially work, but after a couple of minutes all keys start functioning normally.
this problem is occuring for the past few days only. what might be the reason for the occurence of the problem and how can it be solved?
thanks in advance

[Ultragames]

Possibly a program that is runing at start up, that calls for those keys, to be used as possible comands, that then later shutdown. I know some programs wont forward the case pressed to another program.