I have that deck, but not using with Vegas. However, a few suggestions:
1) There is a rotary switch on left side of the deck for "Edit Mode", says things like Player, Recorder, Passive. Try the different options.
2) If using Windows 7, you may need to go into Device Manager and under "1394", try to update driver > manual > select from list and try the "Legacy Driver". You can easily change back, there are 3 to choose from and test with.