This means that due to the limitations of the internal representation, the literal 9.55 is in fact 9.550000000000001 which rounds to 9.56. The same goes for 43.55 but there the representation is slightly smaller than 43.55 so a rounding down occurs.
Snippets of code should be wrapped in
<code> tags not<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).