I found an old post from Frank on the nmrpipe NMRPipe message board that answers the same question, and his suggestion there for processing interleaved data where the IP/AP loop is outside the real/imaginary loop did solve this processing problem. I've reproduced the script below:
#!/bin/csh
var2pipe -in ./fid -noaswap \ -xN 1024 -yN 484 \ -xT 512 -yT 242 \ -xMODE Complex -yMODE Complex \ -xSW 6999.738 -ySW 2000.000 \ -xOBS 499.628 -yOBS 50.633 \ -xCAR 4.773 -yCAR 118.860 \ -xLAB HN -yLAB N \ -ndim 2 -aq2D States \ -out ./test.fid -verb -ov
nmrPipe -in test.fid \ | nmrPipe -fn SOL \ | nmrPipe -fn SP -off 0.5 -end 0.98 -pow 2 -c 0.5 \ | nmrPipe -fn ZF -auto \ | nmrPipe -fn FT \ | nmrPipe -fn PS -p0 177 -p1 0.0 -di \ | nmrPipe -fn EXT -left -sw -verb \ | nmrPipe -fn TP \ | nmrPipe -fn COADD -cList 1 0 -time \ | nmrPipe -fn SP -off 0.5 -end 0.98 -pow 1 -c 0.5 \ | nmrPipe -fn ZF -auto \ | nmrPipe -fn FT \ | nmrPipe -fn PS -p0 0 -p1 0 -di \ | nmrPipe -fn TP \ | nmrPipe -fn POLY -auto \ -verb -ov -out A.ft2
nmrPipe -in test.fid \ | nmrPipe -fn SOL \ | nmrPipe -fn SP -off 0.5 -end 0.98 -pow 2 -c 0.5 \ | nmrPipe -fn ZF -auto \ | nmrPipe -fn FT \ | nmrPipe -fn PS -p0 177 -p1 0.0 -di \ | nmrPipe -fn EXT -left -sw -verb \ | nmrPipe -fn TP \ | nmrPipe -fn COADD -cList 0 1 -time \ | nmrPipe -fn SP -off 0.5 -end 0.98 -pow 1 -c 0.5 \ | nmrPipe -fn ZF -auto \ | nmrPipe -fn FT \ | nmrPipe -fn PS -p0 -90 -p1 0 -di \ | nmrPipe -fn TP \ | nmrPipe -fn POLY -auto \ -verb -ov -out B.ft2
addNMR -in1 A.ft2 -in2 B.ft2 -out A+B.ft2 -c1 1.0 -c2 1.25 -add addNMR -in1 A.ft2 -in2 B.ft2 -out A-B.ft2 -c1 1.0 -c2 1.25 -sub
Here is the link to full post as well: http://tech.groups.yahoo.com/group/nmrpipe/message/389