GD Error after moving gif upload

After uploading a 400px x 400px moving gif image as a user's picture and hitting save a second time, the following php error is thrown:

TYPE php
DATE Sunday, April 3, 2011 - 16:11
USER <censored>
LOCATION http://domain.tld/?q=sites/default/files/styles/thumbnail/public/picture...
REFERRER http://domain.tld/?q=user/1/edit&render=overlay
MESSAGE Warning: imagecolorsforindex(): Color index 6 out of range in image_gd_create_tmp() (line 311 of <censored webroot>/modules/system/image.gd.inc).
SEVERITY warning
HOSTNAME <censored>
OPERATIONS

Details:

PHP version 5.3.3-1ubuntu9.3 using FPM in nginx 0.8.54

php -i:
...
gd

GD Support => enabled
GD Version => 2.0
FreeType Support => enabled
FreeType Linkage => with freetype
FreeType Version => 2.4.2
T1Lib Support => enabled
GIF Read Support => enabled
GIF Create Support => enabled
JPEG Support => enabled
libJPEG Version => 6b
PNG Support => enabled
libPNG Version => 1.2.44
WBMP Support => enabled

...