probably 5.5 is affected too, I didn't check
this is the test case:
What happens here, insert tells the engine to reserve 4 auto-increment values. This "4" number is never reset, so the following load data also reserves four values, even if it needs only two. And the next insert creates a gap in the auto-increment sequence.
Most engines do not reserve auto-increment values, and generate one value at a time. So with MyISAM, for example, there is no gap in this test.
The fix would be to reset the list at the end of the insert statement.