Where one links to a typical page such as:
Where the last character is not a proper A, but instead from the 'greek encoding block':
0000000 316 221 \n
The page on which the link is displayed will, intermittently, appear blank. See http://en.wikipedia.org/wiki/User:ST47/UniLink and try purging the cache or making a null edit, if you can see the page correctly. It appears correctly in previews and diffs, and seems to happen more often on longer pages.
This allows anyone to insert a special link and cause the page to appear blank. It seems to me that the best solution would be to sanitize such links, but I can't tell where this problem is occuring, or if it is a symptom of a bigger problem.
We had an issue with this on enwiki, at [[RMS Titanic]], and there was a discussion at [[VP/T]].