It's not a problem with the BIOS, per se....
It's a problem with Evo-X and how it's launched. Evo-X doesn't like being launched as an app, rather than a dashboard, which is what happens in 4978.03 - and subsequently doesn't handle mapping the D: correctly.
As I've spent a lot of time getting MXM to handle these odd situations, I have a pretty good idea of what's happening. I'm surprised Team Evolution-X hasn't fixed it (rather simple, actually).