No problems here nither. I use Vista on PC. I need to connect to several networks and just have made some tests. I could reach all of them. The fact is that most of them are built on Draytek routers not Cisco, but they also use IPSec and so on.
HTC X7510, MichyPrima WM6.1 R0 Light ROM, Radio 1.58.
HTC X7500 Advantage, ROM: My own ROM cooked in Sogarth's kitchen and using his base. Radio 1.57
TynT II, Official WM6.1 HTC ROM.
i-Mate JasJar, ROM Ivan's WM6 2.05.00.WWE/v4
OS: 5.2.1413 (bulid 179188.8.131.52)
Ext. ROM unlocked