causes top and left properties to be ignored in production environment

causes top and left properties to be ignored in production environment

I have a positioning style that has a .top and .left property that is
being ignored on my production server on some pages and not others.
.logoPosition {position: absolute; left: 10; top: 4;}
The behavior is consistent between browsers and I have flushed the cache
in every case. Everything displays as expected when viewed locally, but
some pages on the production server ignore the top and left attributes.
When I use the IE Developer tools, it confirms that the span element has
the position attribute of the style class, but not the left/top.
So the first problem appears to be definition. The non-working pages have
this definition, while the working pages do not. As I recall, I originally
included this to get hover working in IE, so removing it doesn't work (and
is probably not advised). Are the top/left properties not supported with
this doctype or is there some other issue that causes this behavior.
The next problem is this issue didn't appear until it went to production.
I have read that the rendering mode may be adjusted in the safe zone and
that this may be causing this difference. How can I ensure that my prod
and dev environments render the same.