[Cube] Flashing light

[TonVanHest]

Finally I got my Cube all in proper working conditions again. Took some 
tome because I di not want to use it too much with a videocard that was 
not 100% correctly fitted and I had to wait till today for my ATI 7000 
to arrive.

Howerever the light (on/off switch) somtimes lights up with a really 
very fast flickering (it does not go out fully)!

Is this a sign that something is going wrong or deteriorating or what 
does it mean> Do I have to worry or what?