I've examined the latest version of foo_input_matroska component (as listed on matroska.org download page); it still shows the app-functionality-ruining bug that has been reported over and over: installs a broken directory lister service that prevents foobar2000 core & components from viewing contents of directories; the most visible symptom of this is Media Library rescans randomly ending prematurely with empty Media Library content. This bug has been around for several months at least, it shows that whoever maintains the component probably didn't test relevant code at all as well as doesn't care about dozens of forum threads about problems their code caused.

If you have this component installed, we recommend that you uninstall it. Please don't recommend use of this component to new users.

You can get a replacement Matroska component without critical bugs here: http://haali.net/fb2k/