This is the result of Mathematica 10.0.2 of Linux Version. There are two style inside one tag, and this fragment cannot be Imported as XML by Mathematica.

This is the result of Mathematica 10.1 of Windows Version. This is the right result.
Is this a bug? and is this fixed in Mathematica 10.1 of Linux Version?
item =
Item[Style[Hyperlink["test", "test"], FontColor -> Red,
FontSize -> 20, Bold], ItemSize -> {30, 5}];
ImportString[ExportString[item, "HTMLFragment"],"XML"]
ImportStringcall is part of the test? – Jacob Akkerboom Apr 28 '15 at 15:10