XBMC won't start on Raspberry Pi

I Installed XMBC on my Raspberry Pi over Christmas, very pleased with everything running well, however when I tried to run it this evening it just kept throwing up error messages and continually rebooting, if I disconnect the Ethernet lead it just hangs and despite spending time setting everything up over the last few days I decided that the only cure was to start from scratch and re-install it, however It's still exactly the same (although the Raspberry OS runs fine) after a bit of difficulty I managed to catch the error messages. TIA for any help.

gpu_mem=128
nit: ttyamao main process (600) killed by TERM signal n-dispatcher action:
caught signal 15. shutting down.
nit: disconnected from system bus
nit: delay-start-38 main process (647) killed by a TERM signal terminated
nit: update-checker main process (517) terminated with status