I originally posted this at the end of the tutorial post for DVD Flick, then realized it probably wouldn't be seen for quite a while. Thanks for reading.
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Perhaps someone could tell me what I've done wrong. I double checked all my settings and don't see where the problem could be. Here's what happened:

-added a 698 MB .avi to a new project.....it was the sole title

-chose to just make an ISO, so I could burn later

-normal encoding with second pass

-video encoding seemed to be going fine

-same with audio encoding, although it was taking a bit longer than I expected, especially since I'm using a Core 2 Quad

-the combining started, and went on and on....decided to catch a nap, and was horrified to see the combining still going on at the 8 hour mark

-decided to check the project destination folder to see what was going on....the video file seemed normal at just under 4 gig, but I was shocked to see it had made a 50 GIG AC3 file!! This was my first try, and I really wasn't sure if something was going wrong or not, but I suspected it was, since the project initially told me about 10 gig of space would be required.

-The combined file was approaching the sum of the audio and vid files, so I figured I should at least wait until it reached that point.

-Somewhere around the 55-56 gig mark of the combined file, it finally went to authoring stage....about 15 minutes short of 9 hours at this point.

-I could see it was making the dvd folder that contains the AUDIO_TS and VIDEO_TS files.....figured when that folder reached around 4 and a half gig that it would finalize....well, it continued growing to about 7.2 gig when the following error occurred:

erflow at pack 27239843 by 39515725.54ms
INFO: !tcfound audio PTS underflow at pack 27239844 by 39515631.17ms
INFO: !tcfound audio PTS underflow at pack 27239845 by 39515568.79ms
INFO: !tcfound audio PTS underflow at pack 27239846 by 39515474.42ms
INFO: !tcfound audio PTS underflow at pack 27239847 by 39515412.04ms
INFO: !tcfound audio PTS underflow at pack 27239848 by 39515317.67ms
INFO: !tcfound audio PTS underflow at pack 27239849 by 39515223.30ms
INFO: !tcfound audio PTS underflow at pack 27239850 by 39515160.92ms
INFO: !tcfound audio PTS underflow at pack 27239851 by 39515066.55ms
*** Multiplexing: 99% - 66510812 of 67182638 A/V units. 99%

INFO: 13971556 audio 1 underflows (SCR >= PTS)
INFO:
INFO: NOTE: The resulting file may not play back correctly.
INFO: Try increasing the mux rate.
INFO: Finished multiplexing C:\Documents and Settings\My Documents\DVD\title0.mpg
*** Multiplexing: 100% - 67182638 of 67182638 A/V units. 100%

-The only option was to close at that point, and it obviously didn't finish authoring, let alone finalize. Even if it had finished, would I have had a burnable file? The 50G+ files have me totally confused. Any info would be appreciated.
Thanks!
Spungehead