It is a GeForce with 512 mb of ram.
512 mb of ram is the minimum of running one Wizard101 application, having two will reduce and overheat your graphic cardRAM Space: 512 Megabytes
First off the ram on the card is not the same thing as the ram on the computer. The specs you posted were computer specced ram not card specced ram.
Video Card: Best results with GeForce 2 or equivalent
Almost every card that has 512 ram on it would be above this spec. I think the Geforce 2 series the most the cards went up to were 256 at the time and most were down in the 64 range.
I do computer work and I would say when it happens definately do a reboot. Also reloading the game and reloading the latest video drivers can always help and won't hurt.
Bottom line is if you get this graphics glitch it will stay in memory until rebooted.