I'm also seeing this with a BlackBerry, but haven't had any problems with Sony Ericsson phones; Dell laptops (running Windows XP or Ubuntu); Linux desktops; Acer netbooks (running Ubuntu) and so on.

I'm guessing it's something weird about the BlackBerry - it loves to connect as an AV remote control (until I turned that off), but it refuses to receive files or contacts from my N900 :-(