Ghostwalk error

Running Ghost 11.5.1.2266 and working with a Windows 7 image. I can restore the image but when I run Ghostwalk I get this error:

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Ghost SID Update Utility - Abort dump
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Date        : Fri Jul 23 09:01:21 2010
Error No.   : 0
Message     : Assertion failed: !(( block ) & ~BLOCKRANGEMASK), file DRIVE.cc, line 342
Version     : 7.5.0.335 Build 335

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Memory Manager Details
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Heap Available at start : 0
Current Heap Available  : 0

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Program Call Stack
main
Machine::detect
Machine::detectDrives
Partition::createPartition
FATPartition::detect
Partition::setupHandle
Partition::readSectors
Partition::readVolume
Drive::readBytes
Drive::readBlocks
Globals::abort
Globals::dumpDetails

Drive 0x80 Details
------------------
Parts Cylinders  Heads  Sectors  Mbytes   TotSectors
1          3920     16       32  980.0    2007040  

Drive 0x80 raw partitions
ID Slot Sys   Type        CHSStart         CHSEnd   AbsStart    AbsEnd    Offset   Sectors
00    0  0C   PRIMARY        0/1/1*    123/254/63*        63   2007039        63   2006977

Partition Details
-----------------
Order       : 0
Bootable    : Y
Id          : PRIMARY
First Sector: 63
Num Sectors : 2006977
Last Sector : 2007039
Volume Name :
Volume Type : FAT32

I'm at a loss right now as to what could be the problem.