I use pam_mount to mount a partition. The config line is:
<volume fstype="crypt" path="/dev/sdb9" mountpoint="/mnt/music"/>
When I log in to X, this volume is mounted. Then I open a few terminals, work, close those terminals, and I don't know exactly when, but at some point this volume gets unmounted while I'm still logged in to X. Then I have to open a terminal and "su" to myself to remount the partition. This is clearly not the desired behavior.
I'm using pam-mount that was supplied with Kubuntu-11.04 (the latest Kubuntu).