[This is a re-post of an article I originally published on my now-defunct Blogger-hosted site]
So, you've applied this sweet custom master page to your SharePoint 2007 site and all the pages look fantastic. That is, until you click that Search link in the main nav.
Then you see this:

Notice the end of the word Search is truncated. This is due to the geniuses at Microsoft hard-coding a width of 420px in the search control.
The easiest way I've found to get around this is to add the following to your custom CSS file:
table.ms-sctabarea + table tbody tr td table,
table.ms-sctabarea + table tbody tr td table div
{
width: 100% !important;
} Apparently, there are ways to add a transparent gif or roll your own search feature to accomplish the desired result. However, those either didn't work for me or required too much heavy lifting.
Enjoy.