Letter L in lower-case invisible

Which program triggers the problem? Specify the filename if possible.
Some program using the font Segeo UI, well, I think it's Segeo UI, I'm not sure.

What steps will reproduce the problem?
1. Type words contains l in Firefox search bar.
2. Some programs' menu bar.

What is the expected output? What do you see instead?
it should be File or Help or Little or something, but I see a space where the 
letter l should be. File -> Fi e, Help -> He p, Little -> Litt e.

What version of gdipp (including renderer)? On which operating system?
I'm using gdipp 0.9.1 x64 on a Windows 7 x64.

Please provide any additional information below. Screenshots always help.
Well, every time I try to type something in Firefox search bar, when it comes 
to letter l, it *disappears*. Unless the following letters are typed, letter l 
shows up again. In few cases, the letter l can't been seen at all. Please see 
the attachments below.

Original issue reported on code.google.com by nusush...@gmail.com on 26 Oct 2011 at 2:37

Attachments:

IceMan81 / gdipp

Letter L in lower-case invisible #197