[CentOS] Nvidia Mod Update

Hey all,

On my X86-64 CentOS 6.6 machine I just ran yum update. In the update was an upgrade from the 340.XX Nvidia package to the 346.XX package. Hrmmm? I'm thinking this is not a good idea but, since this is just a test system any way, I let it run. Sure enough I was right. Dmesg says that my video is supported by the 340.XX driver, not the 346.XX driver. It's not happy cause it can't find a supported GPU.

1. So, having only a command line interface, how do I tell yum to rip out the 346.XX package and reinstall the 340.XX package?

2. How do I tell yum not to do such stupid stuff again?