Error while selectiong group! is it the client or the provider?

I was doing just fine last week , i had no problem downloading stuffs from usenetserver using Grabit...but recently, does not matter how old or new the NZBs are i am not able to download at least half of the Rar files!! i get the error that i mentioned above!
Thanks

(forum.shemes.com) See GrabIt forum threads #11099 and #11116, however the participants don't seem to be very serious about troubleshooting this issue.