Time Capsule Error Message

[w0rm]

Hey folks,
Lately my time capsule machine has been acting up and every hour i get an error msg. It basically says that my computer cant repair the backup volume and i should backup ASAP. Then a finder window pops up with a back up folder, and then a time machine error says that it is a read only file and i cant go into anything with it. it was working fine before this and then 1 day it popped up.

any idea's on whats happening?