Checkshape command gives wrong result for compound of 66 solids

Checkshape command gives wrong result for compound of 66 solids.
Each solid Sj (j=1,2,...66) is valid, but compound is not valid.
Use the following Draw commands to reproduce the bug:

restore rx
checkshape rx
#
explode rx
for {set k 1} {$k < 67} {incr k} {
  puts [eval whatis rx_$k]
  puts [eval checkshape rx_$k]
  wait .5
}