hi
You have not stated what operting system you are running, a very important point.
If it is Vista or XP with Service Pack 3 than you will be enjoying the security 'improvements'.
Have a look at
Black Viper's Web Site
for 'tweaks' that will probably solve your problem.
Main thing is to disable all of the MS security stuff.
Might sound foolish but it's the price to pay if you want to have even moderately good performance and reduce your clicking by about 300%!
The 'tweaks' are all safe.
Plus, although there are many who will argue for their own favourites, I would recommend the Cole2k STANDARD Codec pack and 'easy' installation, and the All In One 6.0.3.0 Codec Pack (again with the standard/default settings).
One basic 'secret' is to remove/uninstall your existing Codec Packs, do a restart and then install first
Codec Pack Standard
next
All In One 6.0.3.0
Then, do a shutdown.
Next, start your comp and install the latest
VLC Media Player
The installation order is important.
Last, if you occasionally have problems with VLC and DVD material it is no big surprise and PowerDVD will probably run the DVD without problems.
btw, VLC should have no problems with Matroska files.