Old problems strike back? (No ata1-slave without disk)

Hello,
A problem here: after ATA-MKIII has been committed there's a lot of timeouts 
( "SETFEATURES SET TRANSFER MODE" and after acd1 reinit "MODE_SENCE_BIG" and 
then boot process just hangs) on ata1-slave (DVD-ROM) without disk. 
Everything goes perfectly all right when disk in, but that's not a solution, 
is it? EVERYTHING worked OK before this commit.

Environment: old but reliable 440BX-based  MB (Chaintech 6BTM), the only HD 
(ad0) on external CMD-649 based card, ATA0-master - ATAPI CDRW (acd0), 
ATA1-slave - ATAPI DVD-ROM (acd1). All cables are plugged correctly.

Dmesg output (with my current working setup) is attached

Any additional information?

Regards,
Vladimir