Can you replicate the problem using the default Twenty Thirteen theme with all plugins deactivated?
Forgot to mention: WP 2.5.1, twentyeleven theme. I just “inherited” site management from a former admin.
I was going to try de-activating all of the plugs, since that’s the most obvious source for possible conflicts.
Can’t try anything that would render the site “funny” until the wee hours when traffic is likely to be sparse, but I will get to it soon, I hope.
Oddly enogh, I had enabled WP Super Cache, and then changed the Permalinks to Pretty. When all ^%$#!@+ broke loose (i.e., the Continue reading” links were broken…), I deactivated the cache plug, thinking that was the conflict, but the links problem remained.
Conversely, when I reset Permalinks to Default and Activated WP Super Cache, the caching worked fine and the links problem went away.
Bad typing! It was 3.5.1, but now is 3.6.1, as I just updated WP.
The Permalink problem persists. I am delaying updating the Twenty Eleven theme itself from its current version (1.3) until I can make sure I know what the previous admin did to customize it, if anything. I have updated all of the plug-ins, tho’, without incident.
I just ran into this issue, and discovered that it occurred when the post name was identical to the image name (minus the extension). In each case, if I manually changed the post permalink (shorten it, etc.), so that it no longer matched the image name, the issue would go away, and the posts would display correctly.
Weird! But a short test shows that this is the source of the issue.
Thanks so much for your help!