IPTC maintenance fails with out of memory???

Trying to reload all of my IPTC data to pick up some new tags, the task hung after about 5% and further attempts to restart hang at the "Starting up" phase. Suffering through enabling debugging with a local.php (and running into timezone problems even after setting it in php.ini files, etc), I seem to have the iptc.php file trying to allocate about 3.5GB of memory:

2012-04-27 13:46:07 -04:00 --- error: Kohana_PHP_Exception [ 1 ]: Allowed memory size of 134217728 bytes exhausted (tried to allocate 3864453071 bytes)
/usr/local/src/gallery3-contrib/3.0/modules/iptc/helpers/iptc.php [ 38 ]
#0 [internal function]: Kohana_PHP_Exception_Core::shutdown_handler(NULL)
#1 /av/gallery3/system/core/Event.php(208): call_user_func_array(Array, Array)
#2 /av/gallery3/system/core/Kohana.php(549): Event_Core::run('system.shutdown')
#3 [internal function]: Kohana_Core::shutdown()
#4 {main}

Line 38 seems to correspond to:

                  $iptc = iptcparse($iptcBlock);

Has anyone else seen something like this before? Would it be possible to catch and swallow this error under the assumption that I have a photo or two with a garbage IPTC block (my knowledge of PHP is very slim)? Would it be possible to at least see the file that is likely causing the problem? The lack of debuggability is somewhat frustrating...

Yah, if it was a matter of a couple of hundred megs I would just up it, but I don't think things would improve if I let it allocate 3.2GB (and this is a 32 bit system so that would probably fall over anyhow). I'll see if I can't bulletproof it a bit...