Photo numbering issue SD950 IS

I have been alternating a few SD cards in my SD950 for years. A couple of weeks ago I tested a coworkers SX40, using one of my cards.

I noticed this created a new folder on the card called 111_05 and the numbers started in the 2000's

My pix are normally stored in a folder called 100CANON

I've used the camera a couple of times since then. Tonight I went to download them and couldn't find them.

Turns out the pix in 100CANON were taken through May 13 and end at number 9490

I now have a new folder called  112CANON and the numbers started back at 1!! IMG_001. I of course already have this same numbering scheme starting from day 1 with this camera.

Did I screw this up my putting the card in another camera and not reformatting it? I thought the camera kept track of its photo count internally.

Is there a way to fix it and make it start counting from 9491 again?

Thanks for any help!