If your one of few that get a file manager error when using PC suite for the N-gage QD I've got a solution for you.
Go into PC suite but DO NOT CONNECT YOUR N-gage through your serial port yet! Choose the phone you want to use and click ok so your on PC suite offline. Now go to the manager area and now you can connect your N-gage QD to your PC. You shouldnt get the manager error anymore. If this does not work turn off bluetooth completely from your n-gage QD close out of PC suite and do it over again.
It took me 6 hours to figure this out lol. I even called Nokia about the problem and they stated its one of 2 things.
1. Service packet 2 is interferring with your n-gage or
2. Your bluetooth device is not compatible with your n-gage and pc suite.
But hey I tried this out and it works perfectly I can finally connect to my N-gage again! wOOt.