VLAN problems with 3Com Superstack 3 switch 4200 series

Hello,
I am having problems setting up VLANs on a 3com superstack 3 4200 series switch. I have port 24 on the switch connected to a Cisco 2610xm router and enabled vlan tagging on that port for all the vlans that will go through it. On the router, I have set up virtual subinterfaces for each of the vlan and enabled "encap dot1q vlan id.

When port 24 is "tagged", I can't seem to ping the router's associated IP address for that vlan. If I untag that port, the only thing I can do is use an IP address from VLAN1 and ping the router's IP address on VLAN1. If I try to utilize any other address from any of the other VLAN's and ping the router's associated IP address, it fails.

Has anyone run into a similar situation? It looks like VLAN tagging between the Cisco Router and the 3-com switch is incompatible though the dot1q tag is a standard.

Any help would greatly be appreciated.