accessing ftp server with powered down Hard discs

[froyo]

I"m away from my computer right now, and I want to access my ftp site. I knew this beforehand, so I left my computer on. The system was set to not go on sleep, but the HDDs have stopped spinning (after 30 minutes). I dont have wake-on-lan or anything like that setup. I tried to access my server, got on and through the welcome message. However, the directory listing never came up, and it produced an error. IS this due to the HDDs spinning down, or is it something else (I do have a very unstable system, so there is a good chance that something could have happened during the time I've been away). Thanks