I tried using apt-get install from xterminal same result. I also tried FAM stuck on updating catalogs. my n900 responds fine because I newly flash it. The problem is downloading an app from ham/xterm. 5kb update takes 1 hour to finish.
Then there is a problem with your internet connection. Browsing, emails, cuteTube, everyng else works fast? Then something specific to your connection to Maemo repositories. I would try going to http://repository.maemo.org/ and downloading the packages from there. You can then install them offline by simply tapping on the file in File Manager.