Help for files lost from an external hard disk

Hi all.

I use an external hard disk for backup of my mac with time machine (OS 10.5.8).

I have made something wrong and I have found important folders in the recycler bin. These folders come from external hd. They are backup folders (backups.backupdb) and others.

I have tried to restore them draggin and dropping. Some of them came back in the external hd in a while. For the others it takes hours to "preparing to copy" and then it has said "there's no space to copy" on ext hd.

It's strange. Files are now in the recycle bin (180gb), and the ext had should have lot of free space. But it isn't really so. Ext hd is not free of space even if these files are in the bin.

I ask for advices. I'm not also able to use time machine now (and i have "lost" old backups) for the same reason. Ext hd says that it has not free space..

Thanks and ciao