I experienced this on 1.7alpha (r14665).
In the cologne-blue skin the search field in the menubar can get too big. This is
because the width of
the search field is specified in characters, and not pixels. (or equivalent)

Right now it looks like this:
<input type='text' name="search" size='14' value="" />

Can be fixed with something like:
<input type='text' name="search" style='width: 120px;' value="" />

The error only occurs if your screen resolution is big. (or you have big default
characters)

Related with: cologne blue search field oversize menubar menu overflow

Version: 1.7.x
Severity: trivial
URL: http://www.mediawiki.org/w/index.php?title=Special:Version&useskin=cologneblue