I have same problem as Chris Fonnesbeck with TM2 (9100). Dragging over a long selection shows intermittent skips in highlighting. Selecting by clicking at the beginning, then shift-cliking at the end does not show the problem.
Subject: [TxMt] Scrolling highlight bug in TM2
Date: May 14, 2012 12:40:50 PM AKDT
Running a recent build of TM2, I notice a bug in the highlighting behavior when making a scrolling selection. That is, when I select and drag using a mouse or trackpad, the parts of the editor that are highlighted is inconsistent. Chunks of unhighlighted area appear within a highlighted section. This appears most often when reaching the bottom of the screen, and the text scrolls upward.