thats the second time you have posted that....
you ARE putting a space between "/dev/sda5" and "/mnt/usr/share/swapper" when you type it inot a command line arnt you ?
the file /etc/fstab is a list of all the disks you are allowed to mount without root access.
run the command line as root... after you know it works, THEN you add it to fstab.
if you can mount /de/vsda5 as root, then open up /etc/fstab as root with a text editor, and add the line.....
/dev/sda5 /mnt/usr/share/swapper auto noauto,user,umask=0 0 0
make sure the file ends with a new blank line, then save it.
from now on you should be able to mount without root access with the command line
OR.. you can change the word "noauto" to read "auto" and the disk will be automatically mounted dureing boot up.