The DR-DOS/OpenDOS Enhancement Project

I tried with the DISK.IMG that comes in the binaries .zip file and now both
7.01.07 and 7.01.08 boot (I am using 7.01.07 now, with Lynx browser).
I already noticed some differences:
1) My HD has four FAT16 partitions, one primary and one extended in
the MBR partition table and three primaries in the extended partition
table. MS and PC DOS show their documented behaviour, and detect just
two partitions. DR and Free DOS detect all four. EDR DOS detects three:
the MBR primary and two extended primaries.
2) My video card is an S3 Diamond Stealth VESA VLB and I use a (old)
driver supplied by DiamondMM to improve the VESA modes. This driver
works with aforementioned DOSes, but crashes with the message
"Unrecognized program or filename" if I try to install it in EDR DOS
DCONFIG.SYS.