I was working with today and we did a content deployment of our AUTHORING site to the target site i.e. PUBLISHING SITE. Our Authoring site had pages (web part pages) that were using Content Editor web parts (CEWP) with some static HTML contents.
Now these content editor web parts were not visible on the pages of our Target publishing site even after the content deployment and also our end users were given RESTRICTED READ permission and they were getting ACCESS DENIED errors on these pages (with content editor web parts), we tried to debug the issue and when we got rid of the CEWPs the users were able to browse to the site and were not getting ACCESS DENIED errors anymore, so what was so different about the CEWP, well it was nothing but AUDIENCE TARGET property of the web part in the Authoring site was set to AUDIENCES from an SSP that was now removed from the FARM and hence after content deployment the same AUDIENCE IDs were carried to PUBLISHING environment and somehow CEWP was not working out for RESTRICTED READ permission level.
So the bottom line is if you do Content Deployment and you have AUDIENCE TARGETED CEWPs then the webparts are not rendered on the PUBLISHING SITE, check the AUDIENCE TARGET property and the audiences (GUID) inside it. Check if these AUDIENCES exists in the SSP for that farm.
I dont think this is the problem with CEWP alone this could happen with any other web part also,