The "Can't Connect" issue is addressed in GM9's ever so helpful FAQ, but I'll re-post the fix here:
Quote:
Can't Connect! Please check your internet connection settings and try again later.
This usually means that the auto-updater is blocked by your firewall - you need to make sure that the updater (or java if you start the .jar directly) has access to
http://updater.pala.de:443.
If that does not help, restarting your network router is a good idea.
If you still have issues, note that some users have trouble resolving the domain name above due to a partly broken windows installation. If you have that problem - easily tested by unsuccessfully pointing your browser to the above address - you can use the following workaround (as an alternative to reinstalling Windows):
Go to %windir%\system32\drivers\etc
Open the file "hosts" in notepad and add the following line at the bottom of it:
85.214.17.144 updater.pala.de
Make sure the file is not set to read-only (right click, file properties). Should you not have a hosts file (which would be strange) then just create one with notepad and paste that line into it. Make sure it is just called hosts, not hosts.txt or something like that. But you really should have one...
You may need to restart windows for this to take effect, but then the updater will be able to connect. If the IP of the updater ever changes you will need to manually change this again.