I am investigating this now - MaxSmp problem confirmed. But it all works as expected on the PC version, while there is no immediate obvious difference in the code (though the Mac did requires many changes to control widget gemetries and behaviour).
The message "KEEP:" is the first field in the text string output from "maxsamp2", followed by the amplitude values. It should be parsed and skipped past, but clearly is not on the Mac.
One of the disadvantages of a scripting language such as tcl is that code is never tested for correctness etc until it is used - unlike a stanbdard compiled language such as C, where most syntax or type errors are caught at compile time. Unfortunately, once Soundloom suffers a tcl error, it usually can't recover, there is no workaround, and it just has to be quit and restarted.