Time Machine won't back up

[sun surfer]

Hm, I'm having a problem with time machine. I have an external hard drive that I use for it. I unplugged the external hard drive for awhile, then plugged it back in. But when I plugged it back in, it now says that Time Machine can't back up because there is not enough space - even though the space is taken from previous Time Machine back-ups!

Why is it not recognising its own back-ups on the external hard drive and how can I fix this?

 

[stridemat]

This happens to me every now and again. I normally just double click on the spare image bundle (the physical backup) of Time Machine. This then mounts it in Finder and it normally works from then.

 

[sun surfer]

Thanks, stridemat. Do you mean the back-up on the external harddrive? If so I can't double click to mount it. When I click on it, it just takes me into the back-up itself with all the individual folders and stuff from the back-up.