Problem with links

Been building a site for a friend, have a slight problem in that links are rendered differently in firefox and IE7 and I’m wondering if anyone has any suggestions.

a:link
{
color: #7E7F91 ;
}

a:visited
{
color: #7E7F91 ;
}

a:hover
{
color: #FEF5F6 ;
}

In Firefox works perfectly on both text and images - links appear light grey then white(ish) on hover. In IE7 it works on text but images have generic blue and purple hyperlink attributes. Have tried defining a specific class for the images, have tried !important but nothing seems to work and it’s driving me nuts. Any help very gratefully received.