car lumping a little bit when i let up on gas??

[blaze red mx-3]

I was driving along the other day, i was in 3rd gear at about 3500 rpms. I was slowing down a little bit and took my foot of the gas, the car jump a bit and then went back to norm. When i got going again i tried giving it gas and then letting it up and it kept jumping. Is that just the power of car or is summin up?!?!?!

[gmuffb]

I don't know what it is, but mine does it. The mechanic said that it's normal. So I wouldn't worry about it, unless we're talking about two different things.