I'm using Maverick and this is the setup:
Our router connects us to the company's VPN through which we can access some internal websites. I have to connect also to a customer's VPN in order to use remote desktop and their websites daily.
This customer has a web interface to connect to its VPN, it launches a Java App which signs us in and lets us use the services on their network.
When I do this, I loose access to my company's VPN services (websites) in all browsers. This doesn't happen in the rest of the (Windows) boxes, and I'm the only one using GNU/Linux on the office.
Right now, I log out of the customer's VPN to access the company's services, but I'm sure there's some solution so that I can use both VPNs together.