Upon monitoring system startup for a couple of days i must indeed concure that my so-called workaround was, at best, partial. It really does depend whether emupmixdsp.exe can get going prior to the avast behaviour module kicking in..
If it doesn't (and due to the vaguaries of windows startup ordering - i.e. it's randomness) then you get something like this screengrab taken a few mins after startup...
So... EMU loads in 32 core effects and 235 additional presets, which all look something like this:
(copied from the first .corePresets file, named: {4A71183E-1B9B-4E11-B37F-2BAF5CBEE472}.corePresets )
<?xml version="1.0" encoding="UTF-8"?>
<corepresets abbrevname="Stereo Dela" name="Stereo Delay 250" piaguid="{4A71183E-1B9B-4E11-B37F-2BAF5CBEE472}">
<corepreset factory="yes" name="Default" wetdrymix="0.50000">
<param name="Left Delay Time" type="continuous" value="125.00000"/>
<param name="Right Delay Time" type="continuous" value="125.00000"/>
<param name="Feedback" type="continuous" value="50.00000"/>
<param name="High Freq Rolloff" type="continuous" value="50.00000"/>
</corepreset>
<corepreset factory="yes" name="Slap Back" wetdrymix="0.272059">
<param name="Left Delay Time" type="continuous" value="125.00000"/>
<param name="Right Delay Time" type="continuous" value="125.00000"/>
<param name="Feedback" type="continuous" value="4.017857"/>
<param name="High Freq Rolloff" type="continuous" value="44.19643"/>
</corepreset>
<corepreset factory="yes" name="Panner" wetdrymix="0.404412">
<param name="Left Delay Time" type="continuous" value="210.00000"/>
<param name="Right Delay Time" type="continuous" value="125.00000"/>
<param name="Feedback" type="continuous" value="19.196428"/>
<param name="High Freq Rolloff" type="continuous" value="72.321426"/>
</corepreset>
<corepreset factory="yes" name="Lead Delay" wetdrymix="0.507353">
<param name="Left Delay Time" type="continuous" value="215.00000"/>
<param name="Right Delay Time" type="continuous" value="225.00000"/>
<param name="Feedback" type="continuous" value="59.37500"/>
<param name="High Freq Rolloff" type="continuous" value="72.321426"/>
</corepreset>
<corepreset factory="yes" name="Delay Ringer" wetdrymix="0.455882">
<param name="Left Delay Time" type="continuous" value="244.00000"/>
<param name="Right Delay Time" type="continuous" value="122.00000"/>
<param name="Feedback" type="continuous" value="56.25000"/>
<param name="High Freq Rolloff" type="continuous" value="52.232143"/>
</corepreset>
<corepreset factory="yes" name="Poly Rhythm" wetdrymix="0.257353">
<param name="Left Delay Time" type="continuous" value="250.00000"/>
<param name="Right Delay Time" type="continuous" value="167.00000"/>
<param name="Feedback" type="continuous" value="58.482143"/>
<param name="High Freq Rolloff" type="continuous" value="80.35714"/>
</corepreset>
<corepreset factory="yes" name="Half Rhythm" wetdrymix="0.235294">
<param name="Left Delay Time" type="continuous" value="214.00000"/>
<param name="Right Delay Time" type="continuous" value="107.00000"/>
<param name="Feedback" type="continuous" value="41.964287"/>
<param name="High Freq Rolloff" type="continuous" value="50.892857"/>
</corepreset>
<corepreset factory="yes" name="250 ms Delay" wetdrymix="0.132353">
<param name="Left Delay Time" type="continuous" value="250.00000"/>
<param name="Right Delay Time" type="continuous" value="250.00000"/>
<param name="Feedback" type="continuous" value="12.50000"/>
<param name="High Freq Rolloff" type="continuous" value="60.267857"/>
</corepreset>
<corepreset factory="yes" name="175 ms Delay" wetdrymix="0.235294">
<param name="Left Delay Time" type="continuous" value="175.00000"/>
<param name="Right Delay Time" type="continuous" value="175.00000"/>
<param name="Feedback" type="continuous" value="20.982143"/>
<param name="High Freq Rolloff" type="continuous" value="52.23000"/>
</corepreset>
<corepreset factory="yes" name="167 ms Delay" wetdrymix="0.235294">
<param name="Left Delay Time" type="continuous" value="167.00000"/>
<param name="Right Delay Time" type="continuous" value="167.00000"/>
<param name="Feedback" type="continuous" value="33.035713"/>
<param name="High Freq Rolloff" type="continuous" value="52.23000"/>
</corepreset>
<corepreset factory="yes" name="125 ms Delay" wetdrymix="0.066176">
<param name="Left Delay Time" type="continuous" value="125.00000"/>
<param name="Right Delay Time" type="continuous" value="250.00000"/>
<param name="Feedback" type="continuous" value="12.946428"/>
<param name="High Freq Rolloff" type="continuous" value="37.50000"/>
</corepreset>
</corepresets>
Please note the Byte Order Mark (UTF-8) before the XML definition itself. Would that be the root of the problem?