Problem with ac3 and ffdshow

Hi! Lately, I encountered an extremely strange inability to playback ac3 files (raw ac3) with any given DirectShow Player. I use the latest ffdshow built from free-codecs. And ac3 decoding is enabled in the audio settings. The files will playback perfectly fine in VLC. Also, if I mux the ac3 into mkv or avi, ffdshow will decode them. If I open the ac3 with Windows Media Player 6.4 and check out which codecs are used, for some unknown reason the only Filter Showed is "Ligos MPEG Splitter". (Playback won't start, however the player does not crash or create any kind of error message) Now that obviously doesn't make sense. I tried to fool around with codec merits in the registry but to no avail. If I install a new version of ffdshow it will playback ac3, but only until the next reboot. My OS is WinXP SP2, and I also didn't install anything which would come with Ligos lately. It quite doesn't make sense at all... giev help plz ;))

Use Media Player Classic. That has an internal splitter for .ac3 files.

Yes I know that, the problem is not the general playback of the ac3 (as it does work within a container with ffdshow), it's just that I want to figure out WHY from one day to another this Ligos thing interfers with my files^^

Ok, I have finally got rid of that Ligos MPEG Splitter thing. However, If I try to open a AC3 File in Windows Media Player, it just gives me the message "File not supportet" (this message appears in any Direct Show Player, e.g. Zoom Player). I have ffdshow installed AS WELL as AC3 Filter (no, it's not a conflict, I only installed that after it didn't work anyway). AC3 Audio Tracks in AVI's are played back properly though (by both ffdshow and ac3 filter, depending on merit I set). This begins to piss me off, I want to open ac3 files in Media Player and it worked for years, I don't see why it won't now?! Edit: After messing with GraphEdit it seems that I lack the needed "AC3 Parser Filter". Where do I get that from? OK, I finally got it... Zoom Players Re-Register System Filters did the trick. OMG