I'm impressed that you were able to See ImagineAsian on the 90cm dish!  
     Supposedly an offset dish is more efficent ( mor signal for the size ) than a prime focus dish , because the arms holding the scalar ring , etc. are not in the way .  The scalar ring , etc. are probably in the way too .
     Also , if I had a scalar ring designed for offset ( instead of a prime focus ebay special ) , it would work better .
 I wasnt' able to see it's transponder at all with my 5' dish!
     Maybe an older LNB problem ?  Maybe the dish needs a tiny bit of tweeking ?
A couple gems on C-band DVB are Euronews and Fuse TV.  Sometimes the Outdoor channel has some interesting stuff.   
     Think those channels scanned , and would come in part of the time .   Signal strength & qualit was border line , and faded in and out .
It also has a HD channel in the clear for those with the equipment to receive it. 
     Yes , picked it up a few times on Nexus-S PCI DVB card running in software mode ., again , border line signal .
 I liked BBC World as well.
I need to get a DVB box again...
     Or a card , especially for HD .
Wyr