PcManiac I had the same problem on a C2D e6300. The solution was to delete the PiSegment config.ini file. Next time you run PiSegment gui.exe it will create a new config.ini file.
I have a similar problem with Doomeva's A64 X2-4600. It likes to mess-up its config.ini file if PiSegment is shutdown. When I restart it thinks its a single core. The answer again is delete the config.ini file etc. Now I have a working copy of the config.ini file that I just rename from config.ini.backup to config.ini

Hope this helps
