Unfortunately it doesn't seem to help. sparsebundle seems to get created from NAS web configurator. I even tried different paths for it.
I don't give guests write privileges (since this is in corporate network). Might that be the problem?
Edited later on:
Actually, when I changed the directory of which the Time Machine is stored on the Buffalo device it seemed to help. I did this because I saw that in Preferences - Time Machine had another directory for timemachine backups for some strange reason.
Message Edited by teniemi on 04-17-2009 01:25 AM