Ubuntu Linux 6.06; Linux 2.6.15-26-amd64-k8

I have been playing Under A Killing Moon this evening. Inexplicably, sometimes when swapping discs, the game will complain about being unable to find the file it's trying to load from the disk. Files all show up properly in ls. Unmount, remount, rescan in DOSBox, things seem to work OK. However, many times the initial video that it was trying to play just after the swap will not actually play, or the game will lock up after trying to load a file, or some assets later on after the disk swap (such as inventory videos) won't play until I restart DOSBox. I looked into dmesg, and found that there are tons of attempts to access data that's past the end of the disc. eg.

[79357.303841] sr0: rw=0, want=1254392, limit=1211224 [79357.303843] attempt to access beyond end of device [79357.303845] sr0: […]
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[79357.303841] sr0: rw=0, want=1254392, limit=1211224
[79357.303843] attempt to access beyond end of device
[79357.303845] sr0: rw=0, want=1254396, limit=1211224
[79357.303848] attempt to access beyond end of device
[79357.303850] sr0: rw=0, want=1254400, limit=1211224
[79357.303852] attempt to access beyond end of device
[79357.303854] sr0: rw=0, want=1254404, limit=1211224
[79357.303858] attempt to access beyond end of device
[79357.303860] sr0: rw=0, want=1254336, limit=1211224
[79357.303862] attempt to access beyond end of device
[79357.303864] sr0: rw=0, want=1254340, limit=1211224

The mount command used (in dosbox.conf [autoexec]):

mount d /media/cdrom -t cdrom -usecd 0 -ioctl

I assume this is a problem with the use of -ioctl, but I'm not totally sure about where the fault lies: in the game itself, SDL, the kernel, or DOSBox. Any direction about assisting in debugging the problem would be appreciated. I am running a recent beta copy of DOSBox provided by Qbix with --enable-core-inline and --enable-debug, using the experimental dynamic_nodhfpu core.

To expand this to be a more generic CD-ROM problem thread, DOSBox does not provide a method to release all file handlers on CDs, so sometimes umount must be called with -l in order to make it possible to eject the disc. I wonder if this may be part of the problem.

Cheers,