This is the only similar issue that I could find;http://www.techspot.com/vb/topic103723.html
Of course, all of the parameters and setups are different. Here's what Nvidia said about another 128mb reporting only 64mb;"The issue you are having is hardware issue. I suspect that the memory on the graphics card has gone bad or for some reason is not being detected.
Please note that we at NVIDIA manufacture only the basic chipsets and do not build or sell graphics cards. Our partner companies purchase the chipsets from NVIDIA and they build the graphics cards adding components such as memory, output ports etc.
For the above reason, please contact your graphics card manufacturer for assistance as this is hardware issue."
I'm a bit skeptical though that that's definitely the issue here. with the flashing, and 8x in 4x, I'm thinking it's something else than the ram just suddenly going bad in the midst of it.