Great, Problem solved!
In a test install (this time normal BWP) I encountered this:
Installing [Nazariel The Lich]
Checking for forbidden files ...
Copying and patching 21 files ...
Copying and patching 5 files ...
Copying and patching 5 files ...
Copying and patching 1 file ...
Appending to files ...
Appending to files ...
Appending to files ...
Copying and patching 1 file ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Appending to files ...
Copying and patching 5 files ...
Copying and patching 5 files ...
[action list near line 10515, column 2 of jaheiraj.dlg] PARSE WARNING at line 10516 column 1-20
Near Text: )
[Shout] argument [ESCAPE_AREA_2] not found in [SHOUTIDS.IDS]
[action list near line 10527, column 2 of jaheiraj.dlg] PARSE WARNING at line 10528 column 1-20
Near Text: )
[Shout] argument [ESCAPE_AREA_2] not found in [SHOUTIDS.IDS]
[action list near line 10539, column 2 of jaheiraj.dlg] PARSE WARNING at line 10540 column 1-20
Near Text: )
[Shout] argument [ESCAPE_AREA_2] not found in [SHOUTIDS.IDS]
[action list near line 2116, column 2 of viconij.dlg] PARSE WARNING at line 2122 column 1-19
Near Text: )
[Shout] argument [INCOMING_111] not found in [SHOUTIDS.IDS]
Compiling 1 dialogue file ...
Copying 1 file ...
Extending game scripts ...
Copying and patching 1 file ...
Copying and patching 2 files ...
Compiling 4 scripts ...
Copying and patching 1 file ...
Appending to files ...
Copying and patching 1 file ...
Copying 1 file ...
(Did not get this problem on the weekend...)
I am just guessing: Is the Super Happy Modder component from the Bg2Fixpack necessary or at least a part of the code for the BWP fixpack (?)