This should be a system configuration problem. From
this thread:
http://ubuntu.5.n6.nabble.com/eject-not-working-unless-I-m-root-td4550555.h…
"Your user should be in the group "cdrom" in order to eject
stuff."
I suspect that your user also needs to be in a group for
removable media to be able to eject USB drives.
From a previous post:
Group assignments for my normal user account:
disk lp wheel floppy audio video cdrom plugdev power scanner users
No problems as non-root in Xfce 4.10 and KDE 4.8.5. I never had problems before and group
assignments are the same.
pmount, pumount, pmount-hal are installed 750 suid.
Darrell