Elements appear upon start-up

Sometimes elements of the program appear upon start-up, though I'm not quite sure how to proceed issue-wise.

They include:

Note Entry toolbar - last seen in MuseScore 2.0 Nightly Build (5528) - Mac 10.7.3.

A drop-down box with 'synthesiser'/'audio track' (not sure what this is, though I may have seen it before normally) - last seen in MuseScore 2.0 Nightly Build (5516) - Mac 10.7.3.

I also noticed the diagonal stripes you see in the corner.