Error attempting to process LSMW generated BDC in background via SM35

In our CRM 4.0 system, I used LSMW to create a recording of the Contact Person load transaction (BP). If I process the subsequent Batch Input Session via SM35 in either 'Foreground' or 'Display errors only' mode, everything works okay. If I try to process in 'Background' mode, The job fails with error DC006 - "Control Framework: Fatal error - GUI cannot be reached". My Basis resource feels that this LSMW program can not run in background.

Since I will be loading >100,000 records, I would prefer to run in Background. Does anyone know how to get around this error?

Thanks,

Tony