MMC update is version 1.6.0. Previous version is 1.5.0.
Solution/workaround: SHORT ANSWER Replace mmc executable ver 1.6.0 with 1.5.0
It works, have done it on two desktop systems running 2010.1 (actually my netbook still has 2010 beta so I don't update so 1.5.0 remains)
Get 1.5.0 from these repos and extract the mmc file and replace it in /opt/mmc then mmc works and encodes as you'd expect ...http://kde3.pclosusers.com/pclosfiles/pclinuxos/2007/RPMS.extra/
You'd have to deal with the .rpm somehow to extract mmc. I copied mmc 1.5.0 from netbook install to USB disk to desktop, that was easy.
The original product is athttp://www.miksoft.net/products/
[ ] mmc_1.5.0_i386.deb 25-Aug-2009 16:31 3.9M
[ ] mmc_1.6.0_i386.deb 08-May-2010 08:02 9.0M
Yesterday on 2nd fix on work PC I downloaded the 1.5.0 deb, opened with Ark, extracted mmc executable and replaced mmc 1.6.0 (after renaming to keep it there because mmc 1.6.0 offers more conversion options so it's worth chasing the missing liba52-0.7.4.so file to enable mmc 1.6.0 to do its thing !!) with it.
BTW mmc 1.5.0 is 5.6MB and mmc 1.6.0 is 5.1MB, easy to differentiate.
I tried post suggestion to use WinFF instead but mmc is so much easier, so persevere to get it going again !