i know it prolly sounds silly, but :
i have slackware 10 and mounted the ntfs and fat32 partitions at boot in /etc/fstab
as root i can access everything of course, but as djh i can't get inside /mnt/d /mnt/e etc.
here's my /etc/fstab
/dev/hda8 swap swap defaults 0 0
/dev/hda9 / reiserfs defaults 1 1
/dev/hda10 /home ext3 defaults 1 2
/dev/hda1 /mnt/c ntfs ro,users 1 0
/dev/hda5 /mnt/d vfat rw,users 1 0
/dev/hda6 /mnt/e vfat rw,users 1 0
/dev/hda7 /mnt/f vfat rw,users 1 0
/dev/cdrom /mnt/cdrom iso9660 noauto,owner,ro,users 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,users 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
proc /proc proc defaults 0 0

djh is in group users.. what is wrong there ?

Try setting a umask.

mmm that doesn't sound newbish...
( i have no ideea how to use it and what that does
there's no man entry either

There's a man entry but it's not easy to understand at first, try setting umask=007
That will give all permissions to owner and group and none to others.

Actually that info (about umask and other options) is on mount's man page.