Uploaded images problem after 2.8.1 upgrade

Just upgraded to 2.8.1 on my test server, and now have an issue with images that were/are uploaded to the media library not appearing.

Prior to the upgrade, images that were uploaded to the media library (either via the admin, or the WYSIWYG tool) would be called via the path:

http://sub1.mydomain.com/files/2009/07/myimage.jpg

After the upgrade, no existing images are displaying, nor are images that I've uploaded since the upgrade.The record for the images exists, but there is no way to view the image.

It appears that after the upgrade the path being used by WPMU is no longer pointing to the actual location of the files which appears to be in wp-content/blogs.dir/1/files (or /2/files, /3/files, etc.)

Any thoughts or tips?