.rmvb playback problem with version 6.1.2

[Hugo_Pt]

Hi. I've been using the Vista Codec Package in my Windows XP desktop PC to play .rmvb and other video formats in KMPlayer. Until version 5.9.8 I had no major problems, except an issue concerning thumbnails creation which made programs (Firefox and Samsung Kies) to crash whenever I opened a windows explorer window inside those programs and browsed for video files to transfer.
Now I updated from version 5.9.8 to 6.1.2, unchecking the functionality of thumbnails creation during the installation wizard to avoid the problem I mentioned.
But now, with version 6.1.2, I have a .rmvb playback problem when I try to play those files: they play at an insanely high rate, as if it was jumping frames, and the sound is all distorted. What's wrong?

[HD-False]

I have only one *.rmvb test video and it runs in XP MCE 2005 SP3 plus NET 4.0 properly, but there are other issues with XP and VCP 6.1.X, see for example here!

[Hugo_Pt]

Not me, my OS is Windows XP Home Edition 2002 Version SP3. I have .NET Framework 4.0 too.
I hope the developer will get a solution to the .rmvb problem, otherwise I'll have to uninstall Vista Codec Package and look for another alternative.

[Shark007]

On the Audio TAB, press the button, [setup LAV audio]

[HD-False]

I have disabled LAV Audio and it runs too.