In-page links and IE6
If you are already aware of accessibility issues, it is highly likely that you may also be sensitive to the problems that long pages can create for keyboard navigators. In an effort to increase accessibility, you may well be providing in-page links on long, or complex, pages that are intended to allow keyboard navigators to jump quickly from one section of the page to another without having to press the TAB key repeatedly.
If this sounds like you, then you need to visit Jim Thatcher’s site now!
Internet Explorer 6 has a bug which interferes with the correct working of in-page links when they are selected via the keyboard. Whilst the visual focus within IE6 does move correctly , the TAB focus does not.
In practice, what this means is that, when a keyboard navigator activates a link at the top of a page to straight to the lower section of the same page, the page shifts visually to the lower section. So far, so good. However, if our keyboard navigator presses TAB a second time - perhaps to access another link within this lower section - instead of moving down a little further, they are thrown right back to the top of the page.
Not exactly helpful, eh?
Jim has an explanation for why this happens in IE, as well as a suggested workaround that is well worth considering in his article on the subject hasLayout Property Characterizes IE6 Bug.
Of course, this is just another example of why good usability testing is an important part of accessible web design.