Hi oippi:
Not sure about others but I stopped reading minds when I got married. ;D
Can you share more information about the makeup of your network?? (WAP's, Switches, ect…) And maybe some screenshots of your rules en such.
I have a customer I just put on 2.1 that does meeting from around the globe on Skype... No extra rules, port forwarding or funny dances in front of the router to make it work... Netgears (5 tries) that the cable co. gave him was dropping connections thus the reason I got the job... Not one drop since then. (2.1 (freebsd 8.3) due to needed driver not in 2.0.1 (freebsd 8.1))...
:)