copy pasted in some old post:
"If you have an n-type router, the first thing to do is to turn off the n signal and only use b/g. That might solve your problem, unless you are receiving a lot of signals from other routers in the neighborhood."
If problem continue then check is there thread about that:
https://talk.maemo.org/forumdisplay.php?f=24
and ask there so, another 770 users can find.