hmmm posting the code didn't work. I don't think the code is really important though.. it is the same as I use for anywhere else I use it except it is on an input instead of a div tag.

Not sure this will help, but:

This appears to be a bug in the current versions of Firefox; hopefully the next branch (starting with 1.5) should fix it, but until then here's a simple “fix”.  You need to disable autocompletion on that field.  You do it like this:

<input type="text" autocomplete="off" ... />

You can also disable autocompletion on the whole form if you wish:

<form action="..." method="post" autocomplete="off">

Please let me know if using this attribute solved the problem.