xvid4psp freezing/stops muxing

[AP joe]

I'm encoding a bunch of *.wmv's to HUFF losless *.avi's with xvid4psp. All *.wmv's are from the same source.
All was working well until now xvid4psp just freezes, stops after muxing for a while.
Encoding says 0.00% and just stays there, with the muxing bar about 3/4th way through.

What could this be?

[AP joe]

Some more info:

PLATFORM
------------------------------
OS: Microsoft Windows NT 6.0.6001 Service Pack 1
OEMCodePage: 437
Language: ENU
DecimalSeparator: .
Framework: 2.0.50727.3074
Processors: 2

XVID4PSP
------------------------------
Version: 5.036
Created: 10/18/2008 6:36:32 PM
TempPath: H:\Temp
AppPath: C:\Program Files\Winnydows\XviD4PSP5

FILES
------------------------------
Video18.wmv >
Video18.avi

TASK
------------------------------
Format: AVI
Duration: 01:03:38:200 (57273)
VideoDecoder: DirectShowSource
Resolution: 640x480
VCodecPreset: HUFF LossLess
VEncodingMode: OnePass
VideoCodec: WMV2 > HUFF
VideoBitrate: 2048 > 30896
Quality: 0.444 > 6.705
Framerate: 15.000
SourceType: PROGRESSIVE
FieldOrder: UNKNOWN
AudioDecoder: 0
AEncodingPreset: AC3 640k
AudioCodec: WMA > AC3
AudioBitrate: 128 > 640
Samplerate: 44100 > 48000
SamplerateModifer: SSRC
Channels: 2
Normalize: 90%
Accurate: 3%
Gain: 0.915

VIDEO ENCODING
------------------------------
Encoding video to: H:\Temp\0082.avi
HUFF 30896kbps 640x480 15.000fps (57273 frames)

AUDIO ENCODING
------------------------------
Encoding audio to: H:\Temp\0082.ac3
AC3 640kbps 2ch 16bit 48000khz

MUXING
------------------------------
Video file: H:\Temp\0082.avi
Audio file: H:\Temp\0082.ac3
Muxing to: H:\Documents\2009-africa\2009-06-04 morning\Video18.avi

This last step is where xvid4psp just stops.\
I tried to mux the 0082.avi and 0082.ac3 together with MKVMerge (which comes with xvid4psp) and that worked flawless. But it's an extra step off course and not automatic anymore, like with xvid4psp's batch encoding list.