[rdiff-backup-users] aborted backup, strange error 45?

[Peter Larsen]

0.12.7 / freebsd 4.9/4.10

Used options:
--no-change-dir-inc-perms
--exclude-device-files

-v 7 error messages:
Processing changed file modules.old/vinum.ko
Regular copying ('modules.old', 'vinum.ko') 
to /usr/local/backups/rdiff/laptop/modules.old/rdiff-backup.tmp.695
Writing file object 
to /usr/local/backups/rdiff/laptop/modules.old/rdiff-backup.tmp.695
Exception '[Errno 45] Operation not supported' raised of class 
'exceptions.IOError':

[local]
ls -l /modules.old/vinum.ko
-r-xr-xr-x  1 root  wheel  308911 Apr  6  2004 /modules.old/vinum.ko

[remote] (17% available on device)
ls -l rdiff-backup.tmp.695
-rw-------  1 backup  backup  262144 Dec 25 03:36 rdiff-backup.tmp.695


what did i miss?