I guess "mysqueezebox.com" (button) is enabled, i.e. it's highlighted? Then you are in the new mode where you connect to mysqueezebox.com. If you click the "mysqueezebox.com" button, you disable it, and you get the local server settings.

The new N900 version has been reworked a lot under the hood, so it means that your old settings are lost unfortunately. Here's the change log:
* Player switching bug fixed.
* Optimized startup time. Patrik Karlsson 2012-03-10 12:15 UTC
* Completly new communication core, using http access only (no CLI port needed)
* Remote server support (www.mysqueezebox.com)
* Artists browsing improved - now results in albums and titles
* Rescan music library option added
* Use volume buttons as volume control
* Bug fixes

It turns out "mysqueezebox.com" is the default mode, which I consider to be a bug. I could also try make the switch between local server and "mysqueezebox.com" clearer.

I hope you can get started and proceed with this information.