Paul,
Okay, it looks to me like your mcz file(s) are "corrupted" ... probably
due to a bug in Pharo 1.2 (that's the version you're using right?).
In an mcz file the snapshot of the definitions are serialized using two
formats:
1. a DataStream on an ordered collection of MCDefintions
2. a chunk-file formatted string.
It appears that for the DataStream, the entire(?) stream is written as a
WideString ... WideString is Squeak/Pharo dependent and is not portable
at all ... this is new. When GemStone hits the widestring an error is
thrown and Monticello tries to use the chunk-file format (which is why
you ran into the preamble probelm ... chunk file format is normally hit
(nor is it desirable to hit it)...
The chunk file-file is partially written as a WideString again...because
the WideString is not portable it breaks the parsing algorithms for
GemStone ... interestingly enough the chunk-file string looks to be a
WideString for the first hundred characters or so ...
One of three things is happening:
1. someone in Pharo land decided it was a "good idea" to create mcz
files using WideString
2. The that you used to create the class had a WideString in it
3. there is a bug somewhere in the pharo/monticello implementation
I can't guess which of those 3 the problem is and I can't guess what the
solution might be either.
If you bring up this bug on the Pharo list, I'll monitor the list and if
I can step in and help, I will.
Dale