Sorry, you're right… except that there appears to be a minor bug in jQuery.

If you're setting height or width, and you pass in a -ve value, (eg $(“#foo”).css(“width”, “-4px”), then it goes through the “undefined” case in the above, which then /returns/ the width, rather than setting the width, and returning a jQuery.

That's what was happening, and I just jumped to the conclusion that css always returned a string.

So now I need to track down how colModel.width gets to be < 0. I think it has something to do with autowidth.

In any case, its probably my bug (in that it doesnt show up in firefox) – but I'd still say that its a good idea not to chain the css method when setting width/height by name unless you're certain the width/height is >= 0.

Mark