i use win7 (64 bit) also just without any problem
But if you disable (comment, place # in front of it, or remove that line) of the nativelauncher starter in the servoy.properties then it works fine?
(nativeStartupLauncher=%%user.dir%%\sybase_db\dbspawn.exe|%%user.dir%%\sybase_db\dbsrv11.exe|@sybase_db\sybase.config#Path=%%Path%%;sybase_db;sybase_db\scripts)
Because i think you will get a security dialog anyway because we open up a http port (8080) for the webclient, i think windows will also ask for permissions because of that.
When it hangs is the 8080 port already open? Can you go to http://localhost:8080 ?