Also if you zoom the text, you will notice that the carret is sometime over characters when text is bold.Try disabling font antialiasing (or ClearType) in Windows to see if that effect dissapears. Windows happens to screw some parts of the text if that is enabled.
D:\desktop>ls -a C:/windows/fonts |grep "^[lL].*"
LONDON_F.TTF
Lsans.TTF
Lsansd.TTF
Lsansdi.TTF
Lsansi.TTF
l_10646.ttf
latha.ttf
lucon.ttf
it happens also in SciTE, Wordpad, and in other text editors.This is right! It happens on Wordpad too.