What version are you running? 1.0 Release What's the URL of the page containing the problem? https://reviewboard/r/6235/diff/2/?file=133668#file133668line15 This took some time to narrow down. Here is what I found repros... 1. Create a review request with a diff large enough to span more than one page (ie > 20 files or whatever you have the files per page setting at). 2. Click on the second page of diffs (this is NOT a problem on the first page of diffs.) 3. Scroll down to the file diffs and click the "expand" button for one of the files. 4. Comment and publish on one of the lines that were hidden prior to hitting expand. 5. Now web to another page, then come back so that all the diffs are non-expanded again. 6. Now expand the diff again and notice that the comment flag for your comment is not displayed. 7. Click the *top-level* expand all at the top of the page and now notice you can see your comment flag. (Wow, that's a lot of steps) Multiple users have hit this problem across different reviews and I've also reproduced on my own. What operating system are you using? What browser? Happens in both IE and Firefox (3.5+) This may be related to Bug #381 which is somewhat similiar but not exactly. Further bug #381 is marked as fixed, but this issue is definietly not fixed in 1.0 release.