Had a problem come up last night, on the coldest day of October naturally. When I turn on the defrost button on the centre stack (goes to max defrost and turns on the A/C for it) I can hear the fan blowing but I get almost zero air flow to the windshield. Also, when using the auto climate system (set at 28C) I get heat out of the vents on the driver's side but, I get cold air blowing out of the passengers side vents. The car is still under warranty so I am not too worried about any charges but I am curious if anyone else has experienced this problem and what was repaired to fix this problem? Car is 2007 V50 with 65,500 kms on it.

This is another one of those known S40/V50 quirks. The HVAC servos can get out of sync and it does exactly what you described. I had the same problem about a year ago. Unfortunately, all you can do is take it to Volvo service and have them do their magic (software reload / calibration). I believe that there is a software update that attempts to fix this issue.

Stan