Trouble downloading from Digital Tutors

[Elix]

I know this is the million dollar question on a lot of people's minds, but here it is.

I have a paid account with Digital Tutors. I've been trying to capture the streaming videos from the site with little success. It seems that when I do capture a stream (for example, from this lesson: http://www.digitaltutors.com/11/trai...26&autoplay=1), when I try to play it in a media player that supports FLVs (like VLC), I get an error "No suitable decoder module: VLC does not support the audio or video format "undf". Unfortunately there is no way for you to fix this." Essentially, the video is corrupt.

This ONLY happens when I log into my account, if I don't login and try to download the free lessons, then they capture and play back perfectly. I'm using the latest version of rtmpdump and rtmpExplorer.

I have been successful on one occasion in downloading lessons while logged in, but that was only for a short time, and I have no idea what I did differently. Does anyone have any ideas?