So there isn't like a set destination? The video are approx. 50 megs each... I cleared 2 at a time and checked the space on the sd card before and after and it didn't change... >.<
I can't answer about the destination; I haven't tried to download and store any videos yet. The other response about a "Downloads" folder might be correct. All I can speculate, like others, would be that your downloads didn't complete.
All I've done so far is to copy a 186MB video I created from my PC to my Droid SD card, and it stored and plays fine. So file size for that wasn't an issue.
But the Droid seems to have some problems right now it needs fixes for. I've yet to hear of anybody being able to "share" a video. I can't, and I've seen others say they couldn't. Always get the "File Too Big" error, no matter how small.
Bluetooth file transfers also seem to be limited to around 300KB. I'm just saying that there may have been something like that with your downloads going on - I don't know.