Remote app issues

Hi. I'm having trouble connecting to an iTunes library with remote app. Hope someone can help...

Setup:

Older laptop running Windows XP
Newest iTunes version, standard settings
Connected via cabled LAN (not wifi) directly to D-LINK DIR-615 router
iPhone 3GS w. newest iOS 5 connected via wifi to D-LINK router
Windows firewall disabled, no antivirus installed
Router settings is standard, which as far as I can see means all ports open
Internet connection is via the wan port of the D-LINK connected to a different LAN, which does sit behind a firewall (but this should have no effect on the "inside" LAN, right?

Problem: I can pair the remote app with iTunes, I punch in the four digit code, but the remote app can't find the library.

Where do I go next?

EDIT: Ahem... Nevermind - seems to work now. Next step was: Reset network settings on iPhone. I can't believe I didn't think of that, as that has solved issues in the past... Hope it "sticks". Anyway, I'll keep the post here for future reference. Thanks for listening