Time Machine not deleting old back-ups?

[Khryz]

Why isn't TM deleting my old back-ups to make room for the new ones?

I have 25 GB space left in my TM partition and 35 GB is needed for a new back-up but it keeps telling me it is failing to do the back-up for lack of space.

What do I need to do here?

 

[HockeyGuy]

I am having the same problem... very frustrating. Anyone have an answer?

 

[Khryz]

Okay so maybe this is it:

I got a new MBP which has a 500 GB HDD .. up from a 120 GB HDD on my old MB. My TM partition is 250 GB. I heard I need to have my TM partition 2x the size of my own computer .. correct?

Well I'm only using 80 GB now .. so not sure why that is a problem.