Yes, the problem still seems to be there.  I tried using the GTK+2.10 since
I think that version has fewer leaks of its own than GTK+2.4.  Here are the
results.  Iterations refers to the number of open window then close window
operations.

Iterations     Heap in MB

0                      97
10                    111
20                    127
30                    136
40                    149
50                    153
60                    162
70                    166
80                    166
90                    171
100                   175

Memory growth seemed to slow down after awhile (last 40 iterations increased
heap size by 13 MB, or about 300 KB per window open/close operation).

Using memory analyzer seems to show an increase of around 200 of the following
types of objects for a window open/close sequence:

TUPLE [EV_FONT_IMP]
EV_FONT_IMP
PROCEDURE [EV_FONT_IMP, TUPLE [STRING_32]]
EV_FONT
EV_ACTIVE_LIST [STRING_32]
SPECIAL [STRING_32]

The deltas for these always seem to be identical, so they are probably all
tied together.