[ale] flash ddrives (2)

[zeb]

Messing around, I have discovered something that might be of interest or help.  
I apologize if this is known information.  So here goes:

I have two flash drives.  Both are 1 GB.  The first is a PNY; the second is 
a "MicroCenter"  (that I couldn't resist for $15.95).   

I have a Zip-100 drive, a Castlewood orb drive, and a Western Digital external 
drive attached via USB.  The Zip drive is recognized as sda4, the orb drive 
is recodnized at sdb5.  The WD drive is recognized as sdc1.  I do not mount 
the flash drives on boot, as doing so messes up the mount points (rearranges 
them).

If  either one of the flash drive is plugged into the USB chain on boot-up, it 
is recognized as sdb1 and the remaining USB devices are moved "down" one 
place. That is:  the orb drive becomes sdc5, and the WD becomes sdd1.

If both flash drives are plugged in on boot, the other USB  devicea are moved 
down two places.  The orb drive becomes sdd5 and the WD becomes sde1

After boot with the flash drive unplugged, I can mount either the PNY or the 
MicroCenter drive as sdd1.

I can mount either the PNY or the MicroCenter drive as sde1.

Once I mount a flash drive as sdd1, I cannot mount the other drive as sdd1 
withut restarting the system.  I can unmount and remount that same drive as 
sdd1, but I cannot mount the alternate drive on the same mount point.

The same is true of sde1.  Once one of the flash drive has been mounted on 
this mount point, only that drive can be remounted  on the same point.  

For reference, I am running Slackware 11.0  (kernel 2.4.33.3) .on a very old 
system: (Pentium III (Katmai) at 450 MHz; Asus P2B system board, 392 MB system 
RAM; stock BIOS).

Is there any way to control (force) the order of mounting USB devices on 
boot-up?

If there is an explanation, I would like to "hear" it.  Otherwise, for your 
information and whatever good it may do.

Zeb