I'm starting a new Drupal 6 site so I begin by installed a number necessary modules and themes.  I use drush from the command line for these tasks because it's the quickest way.  When I went to the status report I received the following warning messages:

# warning: file_get_contents(sites/all/modules/devel_themer/ui.mouse.js): failed to open stream: No such file or directory in /svr/www/drupal/includes/common.inc on line 2400
# warning: file_get_contents(sites/all/modules/devel_themer/ui.draggable.js): failed to open stream: No such file or directory in /svr/www/drupal/includes/common.inc on line 2400.

A quick search found this discussion on drupal.org, last updated in May of 2011.

It turns out the solution is simple: after you install jquery.ui you simply copy the ui.draggable.js file into the devel module folder like this:

cp sites/all/libraries/jquery.ui/ui/ui.draggable.js sites/all/modules/devel/.

A refresh of the status report shows the problem is solved.  Apparently, ui.mouse.js no longer exists but once draggable was there the error went away.

Presumably, there will be a fix at some point.  For now the solution is trivial.