It sounds like this could be an MTU issue, you can test MTU size by typing
ping wingate_server -l 1400 (where 1400 is packet size) If this doesn't work then reduce the packet size until the ping is replied to.
If you need to lower the MTU size you can do this on the new version on the network tab by double clicking the adapter, you can view the MTU size on the details tab and change the MTU size on the advanced tab.
If you are not using the Release Candidate version 6 then you can download drtcp(
http://www.dslreports.com/drtcp) from the internet and change MTU size with this.
Regards,
Matt