This sounds like an overheating problem. Did you say you have a Skystar USB? If so, try directing a desk fan at it and see if this helps. Also ensure you have plenty of clearance below the unit for airflow. The internal Skystar 2, especially revision 2.3 but not exclusively so, needs a lot of cooling. I have a 60mm fan pointing at it and this is only just enough on warm days. If you have an internal Skystar 2, the best thing is to try opening a case and pointing a desk fan at it. If this helps, a more permanent solution, such as a small 60mmx60mmx25mm fan (a few pounds at most) somehow mounted onto the tuner module is best. In my case, I have a low profile, half height LAN card next to my SS2 and I've attached the fan on top of this, securing it to the backplate of the LAN card using a couple of cable ties threaded through the fan's screw holes.