Are you sure you are using the latest script, and not some version cached by the browser? When I try it in the Play-Test Applet, with a King move KisjO2isO3 on a 10-wide board, with Rooks (with move mRcR) on b1/i1 and Cannons on a1/j1, it does allow me to do the O2 (but not the O3) castling with the Rook.
Are you sure you are using the latest script, and not some version cached by the browser? When I try it in the Play-Test Applet, with a King move KisjO2isO3 on a 10-wide board, with Rooks (with move mRcR) on b1/i1 and Cannons on a1/j1, it does allow me to do the O2 (but not the O3) castling with the Rook.