1. If your phone is indeed brand new, it might still be running an older firmware version. If you go to your phone application and choose the dial pad, type *#0000# to see what version firmware you have. The latest version is PR1.3 and it´s mentioned in the dialling pad as V.20.2010.36-2

2. HAM (Hildon Application Manager) is really, really slow. Basically you have two options here. Work from the command line with apt-get, or install Faster Application Manager.

3. Try FM Boost, which should improve signal strength of the transmitter.
http://maemo.org/packages/view/fm-boost/

Edit: redundant as others have already posted the same suggestions. Typing is slow on the n900