It seems the Seti CUDA application has a few issues that need sorting out. So I have ceased running it and have returned to cpu-based computing for the time being.
BOINC 6.4.5 also has some issues and shows that it isn't quite ready for CUDA, although it detects and can assign work to the graphics card. It needs some work around scheduling of tasks and cannot currently run a cpu and a gpu version of the same science application.
Just to keep the graphics card warm I have joined GPUGRID. Their application seems to work fine, and keeps the gpu busy for hours on end. A typical work unit takes my 9800GT card between 8 and 10 hours. The only thing I don't like is they have very short deadlines, typically 3 or 4 days.
I managed to hit 2.5 million credits for Seti and 3.5 million credits overall. I am not treating them as a milestone as I am aiming to get Einstein up to 1 million. If all the machines were running it would take about 5 days to get there, but they are all switched off at the moment due to the heat - Current loft temperature is 30 degrees.