What's the hell is "There Is No Disk in the Drive. Please Insert a Disk into Drive \Device\harddisk2\DrXX"?

I own a Nokia 5320 XpressMusic phone and it has a 8GB Fujitsu microSD card. AVG's removable device scan is also enabled. I use Windows XP SP3. When I conect my phone using USB, ofcourse AVG will scan it. After a few seconds, this error appears: "There Is No Disk in the Drive. Please Insert a Disk into Drive \Device\harddisk2\DrXX" (XX means a number, it changes in every error) and it has three buttons, "Continue" "Try again" and "Cancel". I press "Continue" or "Cancel" and it goes away. AVG doesn't detect any viruses whatsoever. I access my memory card after that with no problems but that error is kinda annoying. How to get rid of it and where does it came from? Anyway, I disabled AVG's removable device scan and when I connect my phone again thru USB w/o it, the error doesn't appear.