usb scanner configuration: hpusbscsi, udev

[Thomas Frayne]

I am running on an up to date Fedora Core 3 system, and have installed
sane-backends 1.0.15-1.4 and xsane 0.92-13 via synaptic.  Over the last
18 months, I have periodically tried to get my HP 7450C scanner working
under SANE, but was never completely successful.  I am now trying again,
and am getting similar problems to those I have had before.  I sent a
query to the sane-devel mailing list, and the response suggested that it
would be better to ask on a Fedora mailing list.

My system loaded hpusbscsi, which does not work with sane-avision. 
After much searching I found /etc/hotplug/blacklist and edited it to add
hpusbscsi to prevent hpusbscsi from being loaded.  This fixed scanimage
-L, which now returns 
device `avision:libusb:002:010' is a Hewlett-Packard ScanJet 7400c
flatbed scanner
instead of the incorrect `avision:/dev/sg2' is a Hewlett-Packard ScanJet
7400c flatbed scanner.

Now I find that /dev/scanner-usb-:proc:bus:usb:002:010 is a link to
/proc/bus/usb/002/010, but the device name changes when I reboot.  I
would like to use udev to create a constant device name
/dev/usb/scanner0 for this device.  I put entry

SYSFS{product}="hp scanjet 7400c", SYMLINK="as/Scanjet"

into /etc/udev/rules.d/09-tom.rules.  However, if I unplug the scanner
and plug it back in, the log indicates 
Jan  2 23:34:23 PCasus kernel: usb 2-1.1: USB disconnect, address 10
Jan  2 23:34:26 PCasus kernel: usb 2-1.1: new full speed USB device
using address 11
It has no udev log entry.

Before the device address changed /proc/bus/usb/devices contained:
T:  Bus=02 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 10 Spd=12  MxCh= 0
D:  Ver= 1.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=03f0 ProdID=0801 Rev= 0.01
S:  Manufacturer=hp
S:  Product=hp scanjet 7400c
S:  SerialNumber=87 tem  7400c   
C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr=  2mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=00(>ifc ) Sub=00 Prot=00 Driver=(none)
E:  Ad=01(O) Atr=02(Bulk) MxPS=   8 Ivl=0ms
E:  Ad=82(I) Atr=03(Int.) MxPS=   8 Ivl=10ms
E:  Ad=83(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms

What is going wrong with udev?