Why can't you sign in, is it a problem with your account or the software?
Also, 3.8 has issues with mouse pointer syncing when the program is run in full-screen mode or the resolution is changed. Fixing that is relitavely easy.
Well you may as well check. Follow this address (this if for windows 7, find it yourself if your using a different OS): Control Panel\System and Security\Windows Firewall\Allowed Programs
Make sure toribash is allowed through the firewall.