Small niggle on form presentation

[CookieB]

Why are some of the backgrounds on my text input boxes yellow and some white. Can't see anything different about the definition of each.
http://www.conkercards.co.uk/customer.html
Viewing using IE7.
Any help appreciated
Thanks

[grumpyoldtechs]

its just a feature of IE7

i don't get anything on mine there all white.