I am posting this as someone on the QSI group suggested.
I use the latest version of SGP 220.127.116.1168.
For about a year now the settings on my QSI camera always revert to fans on high speed. Typically the fans used to be on high speed when the cooler was at 100% then they would slow down to quiet mode after the camera had reached the set temperature. Now, that no longer happens and the camera fans remain on high speed. In order to revert to quiet mode I have to disconnect the camera from SGP, open the QSI properties, select quiet mode and then reconnect to SGP.
I think it might be a driver related issue and not related to SGP, but I am posting here to see if anyone has encountered the same problem.
This happens with my 583 and with my 532 cameras. QSI has a protection in the firmware that speeds up the fans if the body of the CCD is at 35 degrees or more. That never happened to me, especially these freezing winter nights.