If the merits are messed up or not quite as they should be then weird things happen- i.e. they are messed up on my system so I get ffdshow AND mpc showing up for video in the same graph (and hence no picture on h.264).Why would MPA being installed cause a problem with AC3filter if you select AC3filter in MP? I thought filters were only used if you had them selected. Did you check your graphs?
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