Dependency on PyQt when using PySide

Hello,

Just trying out the PySide support in matplotlib 1.1.0 and it works great but when it seems that when using the Qt4Agg backend there is a lingering import dependency on PyQt that PyInstaller picks up. My application works with PyQt removed so I assume that this is a PyInstaller issue but I'm wondering if the import structure in matplotlib could be made more PySide+PyInstaller friendly? Thanks.

Stuart