[mythtv-users] missing library midway through Jarod's install, rpm database wedged?

[Dave Stewart]

I'm working my way through Jarod's install doc
http://pvrhw.goldfish.org/tiki-page.php?pageName=rh9pvr250
and appear to have successfully completed installation of the video
capture card driver in step 11.  I can 
# cat /dev/video0 > /tmp/test_capture.mpg
without errors, and with a regular flicker on the disk activity light.

However, when I try to run mplayer I get:
mplayer: error while loading shared libraries: libxvidcore.so.2: cannot
open shared object file: No such file or directory.

I don't claim to be halfway competent at this, but I tried:

rpm -q --whatprovides libxvidcore.so.2

and the response is: xvidcore-0.9.2-2_2.rh9.at

I tried: apt-get install xvidcore-0.9.2-2_2.rh9.at 
and the response is:
error: cannot get exclusive lock on /var/lib/rpm/Packages
error: cannot open Packages index using db3 - Operation not permitted
(1)
error: cannot open Packages database in
E: could not open RPM database

As suggested in Jarod's recipe, I tried:

rm -f /var/lib/rpm/__db*     (worked)
rpm --rebuilddb
error: db4 error(16) from dbenv->remove: Device or resource busy

rebooting and trying again doesn't help.
As I type this in, I'm noticing db3 and db4 in the error messages. No
clue if that's significant...

Any advice would be appreciated.  Thanks,

Dave