Thanks for the responses, guys. I'm not getting any system errors at all. I took it to the dealer last week and they acknowledged the issue, but said that they couldn't find anything wrong with it. On the last night that it was there, they parked it inside and the tech stated that it didn't seem to lower. I picked it up Friday afternoon and am having the same problem. I read the service bulletin that yojek sent above, however our temps are not that cold (though it has been in the teens/20s since this weekend, but warmer than that before then). The dealer had to order a replacement B pillar for a rattle that I have there, so it will have to go back when that part comes in, and I will tell them that the problem persists. I'm sure it's a leak somewhere, but if it's a slow leak, I'm not sure how they are going to find it and then know what to repair or replace.