I'm getting exactly the same problem intermittently, with 6230i/Bluetooth connection. I activate BT on the phone, accept "connect" and PC Suite "sees" the phone. But any attempt to update is met with the same error message that you see. If I power down the PC and reboot, it works - until the next time.
I spoke too soon. Just rebooted and it STILL doesn't work. File manager has worked fine until recently. There have been no changes made to PC Suite, Bluetooth setup or the phone itself. It's ONLY file manager updating that's affected ("Operation could not be completed" - very unhelpful and no help at all in the help menu). Backup and Store Images work fine, so it doesn't seem to be a connectivity issue. Please don't suggest I install PC Suite again, it was a PITA before and, since it worked before, why not now? I've noticed, since being a member of this forum, that help and support doesn't seem to be forthcoming from Nokia themselves, but rather only from other forum members. I thought I had a top-notch, properly supported product; evidently not. Disappointing.