Gigabyte E350N-USB. Crashing while scanning for channels

Hi,
Recently built a HTPC and now every time i scan for channels using DVB Dream or WMP it crashes and the machine re-boots.
I've updated the BIOS, this had made no difference.
I only have a 250w PSU, some people have mentioned this might be the problem? It also makes no difference using the power cable attached to the satellite card either.
Any ideas?
Thanks, Dave
Recently built a HTPC and now every time i scan for channels using DVB Dream or WMP it crashes and the machine re-boots.
I've updated the BIOS, this had made no difference.
I only have a 250w PSU, some people have mentioned this might be the problem? It also makes no difference using the power cable attached to the satellite card either.
Any ideas?
Thanks, Dave