DOS Compatible Card: Open Transport or Classic Network

After installing the System 7.5 Update 2.0, I am unable to do networking from the DOS side of my Power Macintosh 6100 DOS Compatible. I have also tried this on an LC 630 DOS Compatible and a Performa 640 DOS Compatible. None of these are able to do networking with Open Transport, but they work properly with Classic networking.
Apple has released version 1.5 of the DOS Compatibility software and strongly recommends that all owners of previous version of DOS Compatibility cards (except the Macintosh Centris/Quadra 610 DOS Compatibility Card), upgrade to this version of software.

This software requires an upgrade to Mac OS 7.5.3 with System 7.5 Update 2.0. With the Power Macintosh 6100, Macintosh LC 630, and Macintosh Performa 640 DOS Compatibility cards, Classic networking must be chosen instead of Open Transport.
Published Date: Feb 18, 2012