Alright, I\'ve search the jQuery docs (needs somebody devoted to maintaining), I\'ve searched SO, and I\'ve searched Google. I can\'t find the answer to this question.
In the jQuery manual it is stated:
The difference between .css(width) and .width() is that the latter returns a unit-less pixel value (for example, 400) while the former returns a value with units intact (for example, 400px).
Seems like the behaviour of .css() was changed in version 1.3, or at least it seems like that from the bug tracker.
I was trying to find a good (not hacky) solution also, but I haven't been able yet.
Also on SO.