video help

[ssdex]

guys, I am working really hard to make this thing happen, im so confused with camtasia, like i record a 1-2 min video, everything is fine, then i do a 45-1 hour session and the video comes back blank every time. I have the camrec, but its like not saved just sitting in the clip bin and it wont play. I am beyond frustrated, this is the third video I have done and it was a really good one. Has anyone ever had this happen before??? it takes like an hour to upload after finishing, then in preview, only audio plays on a black screen, then after initial preview comes up I can't even get it to play the audio, it wont even start or produce a video. Someone please help me so i can get this thing out to you guys.

-dex