[SOLVED] constant crash and reboot

[aztech]

Hi

I've encountered a very annoying problem recently.
The RPI (model B 512MB)is booting up and entering Kodi, but after that the Kodi interface loads, the menus are very very unresponsive. Usually it takes a couple of minutes before the interface reacts to any input at all.

Usually on input (browse main menu) the screen gets black for a few seconds, but return directly.
After a couple of tries to browse, Kodi crashes and restarts, but now the network is down so libraries and shares are not working and a full reboot is nessesary.

I was thinking that my RPI perhaps has given up on me, OR the power supply is worn out.
It doesn't matter if the Xbian install is new or old, packages updated or not, the result is always the same.

The power supply is not a beefy one and I believe it's a 1.5A generic charger. It this on the borderline, considering that the efficiency degrades over time and generated heat?

What's your advice?
I don't want to buy a new PI if I don't have to.