It seems there are three times it happens , when I lo in and select charectors then it dies trying to load and crashed to a reboot. it also does this when beaming to ground missions , as well as when moving from warp space to a system no error or warning ... just boom reboot ... today was particularly horrible. More so than any other time in beta / closed or open.
Then later today while on the station the error "Client has stopped working" was repeatedly displayed and the game shut down .... after hours and hours of spontainious rebooting and then this silly client dyng randomly I gave up .... any Help , Drivers are as Up to date as ATI offers.
I'm runing the game exceptionally well on same graphic card (Gigabyte Radeon HD4850 1GB) and no crashes at all. I also have the quad-cpu (but from AMD) and everything is okay with it too.
Altrough, all the hardware isn't clocked, maybe that's the reason?
Runing the game on W7 x64 if thats help.
If the game is crashing all the time, and you have the hard reboots I will consider runing some diagnostics, like checking the temperatures, voltages (especially on PSU) under heavy load both the CPU and GPU.
Try with 3DMark, run some StressPrime's and tell what happens.
Edit : Now I saw that you have the 4650 card, not mine. That could change the things a little, but if something is wrong with you hardware the procedure is the same.