I created a new user account in windows 7 (new admin account).
All extensions are disabled on the new account by default.
I installed the webassist extensions in the following order:
1. FreeTools108.zxp
2. WADataBridge118.zxp
3. Surveyor108.mxp
4. WebStandards102.mxp
5.ProMapsGoogle107.mxp
6.WA_SiteImport304.mxp
7.WASocial200.mxp
Then I enabled all the other extensions.
All extensions are now working fine in my Dreamweaver CS6