Board Thread:Support Requests - Getting Technical/@comment-23990955-20140111030619/@comment-1038387-20140111103015

If you use the "Replace Image" function, oftentimes, the image won't go through correctly. Sometimes the ratio is distorted, sometimes the old image still displays on pages. Sometimes both. It's usually a case of waiting for the cache to clean up, 24 hours later.

Wikia is aware of the problem, and last time I asked, they said they were working on a fix.