I have the same problem. I have already written a mail to the list two days ago. I'm running 1.5.4 on Linux with PHP 4.3.10.
This I had not seen. Otherwise I had not written another question on this topic. (Even you are using Linux the reason may be the same.)
Is there anywhere a bug tracker?
Yes: http://bugzilla.wikimedia.org/
With regards, Lukas