I'm not getting an error... but i'm getting nothing - it also shows no sign of installing. And yep I've finished all 21 levels of the initial free game.

Right I found and have run the following in XTerminal to install it:

sudo gainroot
dpkg -i MyDocs/.documents/angrybirds-levelpack1_1_0_0_armel.deb

and hey presto - it's installed. How come this was so difficult... surely this should work automatically when you launch it with app installer?? :-S

It's a confusing piece of kit sometimes...