My mouse and keyboard are A4 TECH KB(S)-2350ZRP set (here are some more details) and when I play a game (not every game about half or 1/3 of the games I have played) they both just stop functioning or react slow.

Details:
Function stopping - the mouse and keyboard stop reacting to my commands and but the last signal doesn't stop transmitting.
Example - if I play a first person shooter and I was walking forward and shooting the character continues walking and shooting.
Note - sometimes only one stops and the other continues to function and sometimes they both stop to function and my computers starts to send out a sound as it I have pressed all the keys on the keyboard at once and the last signals are being resend turnbased (move screen + walk = walk a bit then move screen a bit etc.)

Slow reaction - the computer reacts to my command 1-2 secs after the key has been pressed (sometimes 3-4 secs).
Example - if I tap the walk button the character moves forward a it 1-4 sec after the button has been taped.

Both problems continue bothering me for 5-30 sec. and then reappear 10sec-2/3min. after they have cleared.

Please help.
Thanks in advance.