Ola, NN 4.x Win renders text input fields with a height of 24 pixels, which as far as I could find is the largest (NN 4.x Mac for example renders the height at 16 pixels). Unless you want to spend way more time on it than it is worth I would recommend slightly (2-3 pixels) increasing the size of the header (if you like I could send you another version of the header in simplified html with graphics... I feel there is a better way to cut the graphics that would have prevented this kind of error in the first place).
Torben if Ola gives us the green light (to prevent duplicate efforts), you could work on a stable html version of the content... I could work on the header. Ola?