Here's how mine is configured.
OA13 1,2 are FL and FR
OA13 3,4 are C and Sub
OA13(#2) 3,4 are SL and SR

For the input to the IE42:
DL/R are D4
DC/LFE are D5
DSurr are D6

Kal Rubinson
"Music in the Round"
Senior Contributing Editor, Stereophile