I have a out of the box install of redhat 9 running cups.
I cannot delete print jobs from webmin as they do not
always show up. I believe the reason to be very long file
names, such that there's no separating whitespace between
the file name and size. Ie:
[cebra@yoda cebra]$ lpq
epson3000 is ready and printing
Rank Owner Job File(s)
active samba 15 Cinemaxx.indd
1st samba 16 Microsoft Word - Bakkegrd -
2nd samba 17
From this list webmin only shows the first.