d2v/avs problem

[Curath]

I'm having a problem with .avs files.
DVD ripping went fine, used DVD2AVI to get a .d2v file and so far everything seems fine.
Then I make the .avs file and start up VirtualDub, but it doesn't accept the correctly written .avs.

I've installed the avisynth.dll and also have the mpeg2dec.dll available, yet VirtualDub complains:

Avisynth open failure:
Unrecognized exception!
(C:\test.avs, line 2)

Where test.avs contains the following:

LoadPlugin("C:\WINDOWS\MPEG2DEC\MPEG2DEC.DLL")
mpeg2source("D:\work\test.d2v")

Also tried for 2nd line:
video=mpeg2source("D:\work\test.d2v")