Your tests both work for me in Firefox 4.0 (for the desired effect you are describing).

But your tests are technically not performing the same thing. To mimick what you are doing in the pure JS test you would need to do $('#myselect').val(3); (setting the value on the <select> element) or to swap it around you would need to do document.getElementById('myselect').children[3].selected = true; (setting the selected property to true) on the <option> element)

Aside from that what browser are you testing in?

I'm not sure there's anything we can do here, but I'll take a look. Unfortunately, your first fiddle would not work in all browsers and as Aknosis noted, your second fiddle is not equivalent to the first. One is setting the value of the select, which you can do with val, and the other is setting attributes on the options. However, thank you for putting

together a test case and I put together another test case with val and that does not seem to scroll either (Chromium 12).

http://jsfiddle.net/timmywil/Jd7CE/2/

I don't think there's anything we can do here. Unfortunately setting with .value is not an option even with just one value since if the the value being set does not exist, in IE it will leave everything the same instead of removing the existing selections so we couldn't provide any consistency with the scrolling.