2002 1.4 BBY Auto - Transmission snatch/clunk

[littlepolo]

Occasionally, when slowing down to a crawl at very low speed and then taking off again the transmission snatches. This has happened to the other driver in the household several times. Yesterday I pulled up at some traffic lights and when starting off experienced the same. I'd say it occurs more often while moving slowly and occasionally pulling away from stationary. Not sure what is going on but maybe it is not downshifting properly. Has anyone experienced anything similar to this?