That sounds a bit strange...
I've used my Macbook (and powerbook before this) on MANY routers... in coffee shops, at my house (Netgear), at my university (mostly Cisco, but others are there also), and at my parents place (Linksys and Bay Networks).
I **really** doubt it has anything to do with your router. The forum you linked to shows that some people resolved their issue down to a bad batch of airport cards or logic boards on MBP's, another person found out it was buggy firewall software in his VPN.
Here is a quote from the forum you linked to:
Last edited: Jul 25, 2006