I think that webadmin -> media director -> hardware acceleration vdpau does not affect the profile myth uses.
I do have the md hw accelaration set to vdpau, and with myth "normal" profile it works well (core/hybrid and md), but setting myth profile to vdpau, it works well on the core/hybrid, but hangs on the md, so i've set the myth profile to "normal" on both (core/hybrid and md). I didn't change the deinterlace settings for the normal profile.
on the md deinterlace quality (webadmin -> media director) i've set it to highest.
Under KDE (in any, core/hybrid or md's), open the console window and call mythfrontend.
I guess (just guess) that the problem might be the linuxmce wrap, but maybe one of the developers can give a better answer.