[[ 0*10%300 ]] works on AIX 6.1 but not on AIX 7.1 (ksh)

[[ 0*10%300 ]] works on AIX 6.1 but not on AIX 7.1 (ksh)

I have a ksh93 script that I'm migrating from AIX 6.1 to AIX 7.1

It's failing on 7.1 but works fine on 6.1. Here's a snippet of the important parts.

integer f_count=0
. . .
. . .
. . .
...