My first go at Partitioning in Linux

So myth wants to save its recordings in /mnt/store, which doesnt exist. Time to learn about mounting. YaST has this Partitioner utility which looks like it will be able to reallocate the 100GB that I freed for this purpose on of my windows partition, but it's not playing coz I first need to unmount /windows/C. I figure a good console command to start with is mount, which currently says:

harvest@dell5100:~> mount
/dev/sda6 on / type ext3 (rw,acl,user_xattr)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
debugfs on /sys/kernel/debug type debugfs (rw)
udev on /dev type tmpfs (rw)
devpts on /dev/pts type devpts (rw,mode=0620,gid=5)
/dev/sda7 on /home type ext3 (rw,acl,user_xattr)
/dev/sda2 on /windows/C type ntfs (ro,noexec,nosuid,nodev,gid=100,umask=0002,nls=utf8)
securityfs on /sys/kernel/security type securityfs (rw)
/dev/hdb on /media/SU1020.001 type iso9660 (rw,nosuid,nodev,uid=1000)

So here goes:

umount /windows/C

Said directory is now empty (hope it comes back on its own after reboot!) but YaST Partitioner is still moaning. Tried restarting it, and now I have 100GB floating about free on my disk, somewhere. But where? Create says it's already maxed out on drives. Lets try expanding /home - no luck.

So I'll reuse that 70MB Dell Restore Utility showing up as /dev/sda1, as it's a Windows XP retore thing anyway, which I dont care about any more, and I never used it. Cant resize it currently, so I'm hoping I can after I run this first stage:

Shrink Windows partition /dev/sda2 to 83.0 GB for /mnt/win
Format partition /dev/sda1 (70.5 MB) for /mnt/video with xfs

(you can see I also changed my mount points a little)

Still cant resize /dev/sda1 after format. If I had deleted and recreated it would have come out at 107GB. But now during the delete/recreate I'm getting this error:

Failure occurred during following action:
Deleting partition /dev/sda1
System error code was: -3002

Google search was unhelpful. Turns out closing YaST Partitioner and reopening it did the trick - it had lost the plot again as per last time.