Newly released Program Update 8.0.1489 for Avast 8 has included BSOD fix in AswTdi.sys, Avast hasn’t detailed anything about this on forums. This version has also brought improvements for SecureLine VPN service which has been added with current 8.0.1488 update and other issues to get fixed are WebRep crashes and WebRep for Firefox not saving the position.
You can upgrade to this version through internal program update checker or you can manually download and install this version over existing Avast installation. You may be interested to read How to Uninstall or Remove SecureLine VPN from Avast v8?.