Not sure what happened but try clicking on edit image for the ones with huge thumbnail and then regenerate thumbnail. Hopefully that will fix it. You may need to refresh the gallery page to see the changes.
Bill
Bill Freeman
"A picture may be worth a thousand words, but usually consumes the bandwidth of more than two thousand." --Gym Quirk
Many great words of wisdom and advice http://www.pbase.com/helphttp://pbasewiki.srijith.net/