<< Hmm. Have you compiled the C code and tested it? Just in case... it
wouldn't be the first time that demo C code had some subtle mis-print in
it. >>

Yes, I copied the C source file from the Mersenne Twister (MT) Web site into 
Project Builder on Mac OS X. It ran with out any error. I took the 1000 
numbers and brought them into JMP for statistical analysis. They looked 
great. (JMP random number generators are based on this same MT algorithm 
now.)

<< To check further, knock up a little C prog to take a few numbers and do
the various shifts/masks, and some Squeak code to do the same. Compare;
it should at least illustrate where the differences are creeping in ot
bite you. Chances are good that it is a single trivial typo-like error
somewhere. >>

Thank you for the advice but now I suspect that it is probably not a 
typographical error (confirmed original C source) but a subtle difference in 
the behavior between Smalltalk and C when it comes to long unsigned integer 
operations. I just have no clue!

Again, thanks Tim for looking at this problem for me.

-Mark