Vergil 0 Newbie Poster

Hello guys, not really acquainted with Networking... learning.
I'm having this problem at the moment. A PC of mine connected wirelessly, looses its connection to the router suddenly.
Attempts to repair the connection never works, it always get stuck at the point where it needs to get an IP address (when DHCP is enabled), unable to even ping the router. The solution I came up with was to remove the power plug and insert it in again.
Then I thought of disabling any security features I had enabled..including MAC address filtering, Encryption(WPA-PSK), etc. To see if the problem will occur again. Suprisingly it never did.
My question is..do u think this is actually a Security related issue?
or
Either my Router or Wireless card is in a way faulty?

I should also enquire, since the security feature I'm making use of does have this security "rekey" feature(to my understaning..demands key from clients every time interval).
Do you think the problem occurs during this process of key demanding after the time interval?

edit: I'm sure I have the latest Firmware on the devices