Sounds like a heat issue. If your processor heatsink is not seated properly, or if the heatsink fan stops spinning, your system will shut down like that as a failsafe. Check the retention clips on the heatsink and/or completely remove it and reseat it again. Also make sure that random wires aren't interfering with that little fan, or it will cause the resetting because the processor got too hot. And I don't see why that card won't work with that Mobo, you just might have to flash the BIOS to the latest version.