Some misc. disruptions

Well, I have a Gentoo distro set up, and it seems to work fine. Some minor hiccups, and I hope to get those taken care of.

First: In my Boot screen, I used to see:
Gentoo
Ubuntu
Now I see:
Gentoo
Ubuntu
Gentoo
Ubuntu

I tried going into my boot mamager and deleting the last ones, but they come back..

Also, I can't play .m4a files. I have to use the gmp4player to play them. Anyway around this? (I use BMP for my music)

Third, I can't play some video's. Say I have two .wmv files. file1.wmv plays, while file2.wmv doesn't. Why is this? I have the win32codec's installed, and I'm using MPlayer to use them

Lastly, sometimes when I move my mouse, it'll spazz alittle in place. This results in me drop-kicking it till it stops, or I slam it into the desk, then it works fine. It also did it in Windows before I switched, but not as bad


Thanks for the help