Tim, Darrell,
As /dev/ammo42 suggested, I captured a strace on the i686 crash. It is attached to bug 979. (current tdebase and tqt3, tdelibs from 4/16 -- same crash)
http://bugs.trinitydesktop.org/attachment.cgi?id=568
Also, this bug occurs 100% of the time when pasting 'small' amounts of text (1-2 words at a time) until the line wraps. I can paste 10 lines of text into kwrite and keep editing - so it looks like something that effects the single line length computation.
I'll keep incrementally downgrading and report when I narrow the time the bug was introduced. If anyone can read straces, then take a look.