I feel your pain, I have an nvidia as well. I found that GUIMiner especially hates NVIDIA. I've tried diablo, bfg,rpc miner and guiminer. I find that for Nvidia BFGMiner and rpc CUDA Miner work almost the same, though bfg just feels more stable. I am running an nvidia 570 oc to 900 stock voltage runs about 150Mh/s to 175Mh/s.
BFG: https://bitcointalk.org/index.php?topic=78192.0
RPC: https://bitcointalk.org/?topic=2444.0
BFG: https://bitcointalk.org/index.php?topic=78192.0
RPC: https://bitcointalk.org/?topic=2444.0
Thanks! I'll defiantly look at them! Cheers!
whats your CPU? maybe you can mine litecoin well
Intel Core 2 Duo. Old enough these days. Its next on my list, along with the motherboard, for an upgrade.