Hi,
after a lengthy session of 12 hours I got the following setup to work ok :

Thinkpad running RHEL and a rtl8180 wireless adapter.
Connecting through an AccessPoint to my home network.
Routing to the Internet is working fine as well.

So, that was it........

Not quite. I have a VPN dialer for my company, to connect to the intra-net over the Internet.
This works for my laptops wired Ethernet adapter.

But, when trying to start the same thing through the wireless adapter, it just won't connect.

I'm very puzzled, as the VPN over the wired network works just fine.
Why would it fail over wireless ???
I can see that it is using the correct adapter, and it also reaches the first server on the VPN-server end, but after that all fails.

Could this be due to package sizes ??

Any hints would be greatly appreciated.

just disregard my query above.
After strugling with my thinkpad for another 2 hours, I found the problem.

my firewall rules were not configured for the wlan0 adapter !!!!
(That's what you get with company released platforms !)

So, one of those things you don't think about when you're in the middle of the problem

so, case closed