strange problem with region code 2

[dbento]

I have a LG DRD 8120B which is area free when using rpcman.exe.
What seems amazing to me is that all the 4 DVDs region code 2 I've used seem to have the same side-effect: their playback was slightly faster than it should be. Hence, a movie that should last 90 minutes took only 88. I could never realize that looking, but only hearing. The songs seemed to be half-tone higher than they should.
That problem didn't happen to region code 1 or 4 as I tried same titles with different region codes.
I really don't know if that's a problem of my equipment or of the releases.
Has someone noticed that slight pitch elevation?
What is that? Is it possible to fix it?

Here are the titles I've used for comparison, some of them I could compare to area 1 and learn that only the rc2 were awkward.
(title - region code - company - Country - performance)
1-Miami Vice (rc2- Universal UK - faster than it should be).
2-The Howling (rc1 - USA MGM - correct)
3-The Howling (rc2 - Bridge Entertainment - Holland - faster)
4-The Howling (rc2- BBM - Germany - faster)
5-The Howling (rc2 - BE - Germany - faster)