rdesktop no longer conntects the local folder

Until yesterday, this command successfully connected my local folder and made its contents accessible from the remote Windows machine (Microsoft Windows Server 2003):

$ rdesktop ip.add.re.ss -u username -p passwd -g 1200x800 -r disk:diskname="/home/linuxuser/sharable"

The server in question is intensive use one, so I can not do the Windows restart ritual to fix things. So I'd like to find out if this is something at my end. The command used to work, the drive is just not mounted on the remote. No error messages neither on guest nor host.