My router has a firewall which might be the reason, but I see no reason to enable it for two apps (one of which is broken anyway: I managed to accidentally run a dist-upgrade via apt-get on the N900, which totally breaks Nokia's program manager — no more updates though, so no point reflashing the thing).
Trust me, I'll use the CPU, but not for office documents. I'd use 4 GB RAM too if I could get it; I use it on my laptop. I do software dev., and compilers, besides some IDEs like kdevelop, are pretty memory hungry.
You want to do software development on a smartphone?
Very futuristic :P I guess even a dual core 1,4gHz ARM isn't going to do you much good ;P