Zooming on Chrome causes CSS positioning issues
You can use em positioning which will reposition and size based on the font size. So when people do like control + or command + then the page will auto resize. Here is a page about elastic layouts. Hope this helps.
http://v1.jontangerine.com/log/2007/09/the-incredible-em-and-elastic-layouts-with-css
In my experience, using a left: px value and a top: px value compared to left/bottom right/bottom or right/top seems to do the trick. This applies to both Chrome and FF, can't comment on IE.
For example:
#my-element{ list-style-type: none; position: fixed; left: 54px; top: 40px;}
Although this is an old topic, I stumbled upon this problem. Fixed by adding wrapper containers to the "elusive" elements. So before trying to fix the element css maybe check and make sure the content wrappers first.