Scanner-Problem with Kernel 2.2.9

[Andreas Tille <tille@physik.uni-halle.de>]

Hello,

recently I posted a problem with find-scanner from sane with all the current
potato packages instelled. The kernel is 2.2.9.  I've got the hint to
try strace.  I'm really not familiar with strace but perhaps I've
found the source of the problem in the following lines:

open("/proc/sys/kernel/sg-big-buff", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/dev/scanner", O_RDWR|O_EXCL)     = -1 ENOSYS (Function not implemented)
open("/dev/scanner", O_RDWR|O_EXCL)     = -1 ENOSYS (Function not implemented)
open("/dev/scanner", O_RDWR|O_EXCL)     = -1 ENODEV (No such device)
open("/dev/sg0", O_RDWR|O_EXCL)         = -1 ENOSYS (Function not implemented)
open("/dev/sg0", O_RDWR|O_EXCL)         = -1 ENOSYS (Function not implemented)
open("/dev/sg0", O_RDWR|O_EXCL)         = -1 ENODEV (No such device)
open("/dev/sg1", O_RDWR|O_EXCL)         = -1 ENOSYS (Function not implemented)
open("/dev/sg1", O_RDWR|O_EXCL)         = -1 ENOSYS (Function not implemented)
open("/dev/sg1", O_RDWR|O_EXCL)         = -1 ENODEV (No such device)

In fact /dev/scanner is a symlink to /dev/sg1.

The problem in opening /proc/sys/kernel/sg-big-buff seems me caused by
a kernel problem.  Is this assumtion right?  What do I have to do?

Kind regards

           Andreas.