It appears this is usually caused by the changes file made bad by 
Stuffit or by not downloading in binary mode. Generally people seem 
to be saying download in binary mode with an ftp program, then be 
sure Stuffit Expander cross platform preference is set to 'Never 
convert text files to Mac format'.
There is supposed to be an answer to this problem in the Squeak FAQ 
on the Swiki. See <http://minnow.cc.gatech.edu/squeak.471> but I 
tried just now and could not get through. I have previously had weird 
corruption problems after what appeared to be successful Binhex 
decode until I recently upgraded to Expander 5.1.3.
    Ken

At 21:09 -0400 on 99/10/17,  Lee Phillips is rumored to have written:

>Hello,
>   I'm just starting out familiarizing myself with Squeak. I am very 
>impressed with this environment. I have tried Squeak 2.5 & 2.6 for 
>the PPC Macintosh, and I have a problem with the system browser. 
>Often the definition or commentary for an object has its first few 
>characters chopped off. Can anyone help?
>
>   Thanks.