affected ros r72892,r72896, and older (at least since a year)
I can reproduce this with Wordpad, which uses RichEd20.dll
Tahoma font size 12
words: certi*fi*cate, *fi*refox, Of*fli*ne
The issue is gone when replacing our Tahoma font with the MS-versions.
The issue is also fixed when using RichEd20.dll from WinXPSP3 v220.127.116.110
The symptom started to show with commit r62982 (Winesync Riched20)
The same words show the same visual glitches in Firefox28, this case is handled in subticket.