Blackberry App world Download not working.....?!

[lalala4]

First time posting so sorry if i've written in the wrong section or something..

I have a blackberry curve 8520 and im on t-mobile..

The other day i tried downloading an app and this message showed up:

'There was a problem during installation. Please try again'
'Blackberry app world is having trouble connecting to the blackberry app world server. verify your network connections and try again.'
and now im really confused because everything was working fine- my internet, bbm, other apps like facebook- they all work just fine.
And it wasnt the app i was trying to download because i tried downloading other apps just to check and on all of them they would start downloading but a few seconds later that message would pop up.
pleaaaase help me . x