TB6 and Quicktext working fine! Rated 5 out of 5 stars
To avoid problems with TB6 and quicktext:
Try first upgrading TB, then remove the (old, deactivated) version of Quicktext, restart TB, install Quicktext _new_ from here: http://extensions.hesslow.se/extension/4/Quicktext/, then restart TB.
Result: Works perfect for me. Best: the "Quicktexts" from your old setup are still installed. I worked with version v 0.9.11.1, downloaded today (August 19,2011).