>>>That means that the leftmost bit is set
>>>
>>>Did you try UInteger instead of Integer data type ?
>>>
>>>UInteger cannot be negative http://msdn.microsoft.com/en-us/library/x79h55x9(VS.80).aspx
>>
>>There is a lot of Integer declarations in there. Which one specifically should I try that adjustment on?
>
>
>(1) The short way is to cast the return result to UInteger, and change the return type of GetCrc32() to UInteger

IIRC you can't do that cast in VB (although you can in C# using 'unchecked')
>
>(2) A bit more work is to change everything that is involved in the result to UInteger
>
>At first glance
>class level
> - nCRC32
> - nCRC32Table
>
>
>in Initialize()
> - lnDWPolynomial
> - lnDWCRC
>
>in GetCrc32()
> - lnCRC32Result