When you store a script attached to a data table, JMP parses the script and stores a parsed version. This has a side affect of sometimes changing the script when it's redisplayed, especially when there are equivalent functions and operators.
JMP 8 does a better job of restoring your script just as entered.
Did you right click on the script screen the select reformat script? I have seen some strange reformats when I do this, but none that change my variable declaration to using doulbe semi-colon (::) . I use JMP 7 though.