2005 Auto transmission downshift problem

[hattrik21]

58k on the odometer
Auto tranny
Tranny fluid changed about 3k miles ago.

I had to slam on my brakes today as someone pulled out in front of me and I pretty much stopped but then was able to let off the brake and start going again. For about a second or so the RPM's reved up and then the truck jumped as it seem to catch the gear. I thought it was odd but thought I'd test out this in an empty parking lot and every time I slam on my breaks or come to a quick stop and then a quick go again this happens each time. If I wait 2-3 seconds before going the issue isn't seen.

Downshifting for passing or slowing for turns is fine as well. It appears to me that it is an issue downshifting to 1st only.

Anyone have any ideas or should I just take it in? I've verified that the fluid level is full. It's reading about half way up the HOT side when it is hot. I haven't been able to check the level when it's cold.

I'm not seeing any lights on the dash either.

Thanks in advance.