Memory hog on Ubuntu 9.10

[Yang Zhang]

I'm using Ubuntu 9.10 on x86_64 with Compiz effects turned on. No apps
are running, but according to top, X was using 733MB:

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 1461 root      20   0 1145m 733m 8716 S    0 36.6  16:05.56 Xorg

xrestop shows programs taking nowhere near a gig:

xrestop - Display: :0.0
          Monitoring 37 clients. XErrors: 0
          Pixmaps:   23907K total, Other:      93K total, All:   24000K total

res-base Wins  GCs Fnts Pxms Misc   Pxm mem  Other   Total   PID Identifier
1000000     4    3    0   17  179     9000K      4K   9004K  2977
gnome-settings-daemon
1800000    45    2    1   22  796     7124K     20K   7145K   ?   compiz
1c00000    17   46    1   31  764     2420K     20K   2440K  3070
x-nautilus-desktop
0000000     3    0    2    0   76     2250K      3K   2253K   ?   <unknown>
5200000     0    0    0    1    0     2250K      0B   2250K   ?   <unknown>
1e00000    28   65    1   26   72      753K      4K    758K  3127
gtk-window-decorator
4400000     5   66    1   20   67       64K      4K     68K  3244 ~
1a00000    43   67    0   21   98       20K      4K     25K  3069
Bottom Expanded Edge Panel
3800000     4   39    0   10   16       15K      1K     16K  3141 System Monitor
3600000     5   62    0   10   43        9K      2K     11K  3085 Do
5000000     1    1    0    0  229        0B      5K      5K   ?   <unknown>
3200000     2    1    0    1  217        4B      5K      5K  3091 Tracker
2800000     6   64    0    9   29       15B      2K      2K  3100
gnome-volume-control-applet
2600000     6   56    0    2   20        8B      1K      1K  3092
gnome-screensaver
2400000     6   32    0    2   26        8B      1K      1K  3096
gnome-power-manager
3a00000     4   33    0    2   13        5B      1K      1K  3143 Weather Report
2200000     4   32    0    2   12        8B      1K      1K  3080
NetworkManager Applet
3400000     4   33    0    1   10        4B      1K      1K  3115 Trash Applet
0200000     0    1    1    0    0        0B      1K      1K   ?   <unknown>

Once I log out and back in, the consumption drops back down. Somehow,
over time, consumption manages to go back up. I'm not sure if it's a
gradual leak or a sudden step.

Below's my xorg.conf. Any ideas? Thanks in advance!

Section "Monitor"
        Identifier      "Configured Monitor"
EndSection
Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
        DefaultDepth    24
EndSection
Section "Module"
        Load    "glx"
EndSection
Section "Device"
        Identifier      "Configured Video Device"
        BusID           "PCI:1:0:0"
        Driver  "nvidia"
        Option  "NoLogo"        "True"
EndSection
-- 
Yang Zhang
http://yz.mit.edu/