This problem has plagued my STT8300M since my original purchase of the camera new about 2 1/2 years ago. The problem is that fairly often (several times a night) the filter wheel will get stuck moving between filters. At least that is what the ASCOM driver is returning to the control program SGP (Sequence Generator Pro). I have never physically tried to check that the wheel was actually stuck in some mid-position. The image control program just gets a failure response from the ASCOM driver after a filter change request, and therefore halts its taking of images. If this happens when I am no longer monitoring the session, then I get no images for the rest of the night. Here are the relevant details: 1) When the camera exhibits this filter stuck in moving state, I can fix it in 2 possible ways. First I go to the filter control panel where you can choose a specific filter and click the Set button. This usually causes it to successfully load the chosen filter. If that does not work, I have to disconnect the camera via the software, power it down, wait a few seconds, then power up and reconnect. This generally works (see following item on temperature dependence). 2) When first powering up the STT8300M and connecting to it under ASCOM, about 1 in 3 times it comes up in this stuck state. I have modified my SOP to always specifically check that the initial filter is successfully loaded when the camera is first connected. This has become more of a problem with recent effeorts to fully automate my observatory. 3) Somewhere between 50 and 200 filter wheel changes can be made before this failure appears. 4) There appears to be a significant temperature dependence on the frequency of failures. It fails at temperatures in the 60s F and 50s F and much worse with temperatures in the 20s and 10s. The colder temperatures usually require the power down/power up sequence to reset the filter. 5) I have tried both USB and Ethernet connections. Fails with both. 6) Last fall I had to return the camera to Bill for a complete replacement of the motherboard, which had totally failed. Unfortunately, out of warranty. I had great hopes that would completely solve this problem. Actually, if anything, it is worse. So I have a brand new motherboard and the problem is still there. 7) SGP has many users with STT8300M cameras. None have posted any filter problems on the SGP forum. I have tried to deal with the failures by drastically changing my imaging sequences to try to minimize filter changes. I may take up to 10 images before changing to the next filter. It still fails a couple times a night. Bill is at a loss as to what might be causing this. Hopefully others may have some good ideas how to fix this. What components in the STT8300M could be causing this? What can we replace to try to fix it? Has anyone else seen anything like this?