samba - Apr 2006 - smbfs mounts become unusable after Windows reboot

Hello.
I'm using samba 3.0.22A and Linux 2.6.15.
I mount my shared Windows drives through /etc/fstab. The corresponding lines 
are:
//raviv1/c  /mnt/raviv1/c  smbfs  
uid=0,gid=0,username=x,password=x,iocharset=utf8,codepage=cp862  0  0
//raviv1/f  /mnt/raviv1/f  smbfs  
uid=0,gid=0,username=x,password=x,iocharset=utf8,codepage=cp862  0  0

This works just fine until I have to reboot the Windows machine (Windows 2000 
Pro SP4)
After a reboot the mount-points become unusable and cause some long freezes 
when trying to access them. I cannot even umount them properly, nor with 
the -f flag, so in order to fix this I often need to reboot my Linux box 
(because I'm not sure exactly what else to do).

Is it possible to prevent this behavior somehow? To make the system remount 
those shares, or re-look for them?

In case that's impossible, how can I reattach those mount points without a 
reboot?

Thanks a lot,
Shahar.