I think the errorbox information refers to Elecard MPEG2 Demultiplexer?
DivX 5.05 is not up-to-date. We have version 5.2.1 at present. So the Mega Codec pack (and all it contains) you installed must be quite old too. It is better to install codecs and filters individually (and certainly no more than needed). This also enables individual updates.
Especially read item (4) of my
Help2Help-post (at the end of which there also is a link to
adicoto's list of codecs).
P.S.:
Yes
adicoto means "in addition to".
There are lots of places where you can find
DivX 3.11 Alpha codec or the
DivX Audio Compressor (which contains the DivX ;-) Audio codec that came with DivX 3.11 Alpha). E.g. check out these links
one,
two,
three and/or
four.