CSS Image Placement

[Hexidecimal]

Hi all

I'm working on this site.

The rounded corner images I'm using for the navigation stay in place on IE and FF on 17" but I've just noticed on IE on a 21" monitor they do this and this.

I haven't been able to fix it yet, is there anyone out there that can help? Please.

Thanks.

 

[iCraig]

At 1600x1200 on my 21" it looks fine

At 1280x1024 on my 17" it looks fine

This is in IE.

 

[Hexidecimal]

This one is at 1024 x 789, not sure bout 1600 x 1200 as I think this is an old PC and that is the highest res available.