I am running the new GNS3 v0.8.1 VBE all-in-one and GNS3 v0.7.4 all-in-one. When I try to open the 8.1 I get the error unable to open port 7200. However, when I close all the way out of 8.1 and open 7.4 version all works fine. The old version is able to communicate over 7200 TCP port. Should I uninstall the old version and try it again with 8.1 version? I have dynamips pointing to the new directory that it create when I installed GNS3 v0.8.1. Any help much appreciate.

What happens if you point it at GNS3/dynamips-wxp.exe ? (i.e. use "dynamips" from original GNS3)
Does it help?
Try change port.. 7201, 7202 - does it help ?

I copied dynamips-wxp.exe file to new directory created for VirtualBox version. You will find this file for those interested in your original install of 0.7.4 version. I tested the IOS images and all seems to be running smoothly.