ATAng primary-secondary drive oddness

[Barry Miller]

None of the previous posts on this seem to describe exactly what I'm
seeing:

5.1-REL always detects the secondary drive.
5.1-CUR never detects the secondary.
5.1-CUR + ata-lowlevel 1.11 detects it the FIRST time it's booted
immediately after 5.1-REL.  Always.  On subsequent boots, no luck.

A = 1st CUR + ata-lowlevel 1.11 after running REL.
B = 2nd and following boots of same.

B ata0-slave:  stat=0x10 err=0x01 lsb=0x00 msb=0x00
A ata0-slave:  stat=0x50 err=0x01 lsb=0x00 msb=0x00
A ata0: reset tp2 mask=03 stat0=50 stat1=50 devices=0x3<ATA_SLAVE,ATA_MASTER>
B ata0: reset tp2 mask=03 stat0=50 stat1=10 devices=0x1<ATA_MASTER>
A ata0-slave: pio=0x0c wdma=0x22 udma=0x45 cable=80pin
A ad1: setting UDMA100 on Intel ICH4 chip
A ad1: <ST340014A/3.06> ATA-6 disk at ata0-slave

I'll provide more info or try something different if it might help.

-barry