how can I umount or reconnect a share after the share provider reboots?

I'm connecting to a couple of shares on an XP Pro workstation - not a
good idea, I know, but it's convenient in this case except:

sometimes the XP workstation gets rebooted while the shares are
connected. After that, I can't disconnect them and I can't reconnect
them. This creates a real problem because some programs (esp. under
wine) seem to read the full /mnt folder so they take forever.

I've tried umount //server/share --force as root but it doesn't work. I
get 4 or 5 error messages telling me things like the device is busy, etc..

To be clear: there are no processes that should be keeping the share
from being unmounted. The problem is specifically that the workstation
providing the share has rebooted. If it hadn't, umounting would work.
lsof and fuser both return errors, presumably due to the discrepancy
between the what the mount table thinks is mounted and what I really
have a connection to.

Any solutions?

 

That's one of the reasons why I prefer to use autofs with a rather short
timeout for smb and other shares: I cannot forget to unmount them.
However, keeping a shell or file viewer open on the mountpoints prohibits
auto-unmounting and then there is a hang.
When you are certain no write access has to be performed, mount the shares
r/o and after everything else fails, remove the offending entry
in /etc/mtab, as a workaround.