updating thumbnails?

[NOP]

I've got a couple pages that I've been working on, and I recently updated new images over the top of the old images I had.
The problem is that the thumbnail for the image still shows the old image, and I've not found a way to get the thumb to update to reflect the new image behind it.   can this be done easily by me, or should i just nuke all the old links and upload fresh images?

an example:
http://wiki.arcadecontrols.com/wiki/RL_tutorial_firstList

click on the first image there and you'll see the fresh image, but the thumbnail is stale.

thanks!
-jeff!

[NOP]

ok, dunno what magic elf updated them (or if it's a nightly thing perhaps) but they all seem fine now, so nevermind!