I've been having the same problem for almost a year now when I open the door to insert a tape. It eventually goes away but always returns.

Hi, I've never posted here before and I'm no expert on any of this. However the reason I came across your post is that we have the same camera and recently it has developed exactly the same fault - i.e it repeatedly says there is condensation when there clearly isn't. I know there isn't condensation because if there were genuine condensation it would have cropped up during the 2 1/2 years we've had the camera instead of repeatedly just in the last few weeks. Also we've had occasions where it's been working fine and suddenly stopped working and flagged up the error, despite it's not having moved from the same spot in the same room. The fact that you've had the same fault suggests to me a design fault or over-sensitivity issue with the condensation sensor. I'll try and chase JVC about it but like you, our camera is well out of warranty so might not get anywhere. I'll keep you posted.