Version: 1.9.5 (using KDE 3.5.5, Kubuntu (edgy) 4:3.5.5-0ubuntu3.1)
Compiler: Target: i486-linux-gnu
OS: Linux (i686) release 2.6.17-10-generic
This behaviour started in the last version of Kubuntu (Dapper) and I thought maybe there's something wrong with my system. I even changed my machine (now having a Core2Duo processor) and KMail still shows this.
The Compose window behaves very very slow; I type entire sequences of words and they get on the screen one letter at a time at a rate of one letter per second.
The System Load shows a dramatic increase in processor usage, only for composing new messages.
Other programs (even a word processor) behave as usual, but switching to the Compose window almost freezes it.
I hope I was explicit enough,
*** This bug has been marked as a duplicate of 119281 ***