Trouble using marks

Hi,

For some strange reason, I'm unable to draw marks with IPE on my
computer.  What happens is the following:

I can draw text, lines, etc just fine.  But if I try to place a mark, it
is not shown.  However, the object is there, I can select it and change
its properties and so on.  Then, if I try to draw something else, like a
line, after having placed the (unseen) mark, it also won't be drawn (but
the object will be there).  If I delete the original mark, the line that
I drew after the mark becomes visible.  A similar issue occurs if I try
to draw arrowheads: they won't appear, but after I've drawn them I can
still draw other objects properly.

I've tried both the IPE version in the Ubuntu repository (7.0.14) and
the most recent one (7.1.1).  My machine is running Ubuntu 11.10.

It seems to me that this happens because of some misconfiguration or
broken library on my machine, but I'm at a loss on how to debug this
properly.  Does anyone have pointers to what the likely culprit is, or
how I should debug the issue?  I just started using IPE yesterday, so I
apologize in advance if there is a trivial answer to this.

Regards,
Per Austrin