Time Machine not doing anything.. HELP!

[Arkanok]

I turned my external drive on, let it be for a short time, and looked in the finder window only to notice that time machine appeared to still be backing up! So I opened my System Preferences, and into the time machine settings. The progress bar just seemed to be stuck on "Preparing" and not really going anywhere. So I stopped it, restarted the computer, and retried the backup... Guess what? Same thing happened. Its still just stuck on "Preparing".

Can anybody help me please?

 

[Bigtree]

What type of hard drive?

 

[Arkanok]

What type of hard drive?

Lacie 500gb USB 2.0.

 

[Silverbird0000]

I know that the first time I opened time machine and it started it's first backup it took about 3 hours to back up everything. After the initial backup, it only takes a minute to do backups.