beginner with few problems

[cannonfauder]

I upgraded to 1.7.2 and found that

1) mantra theme didn't work anymore but changed to default and system works are they a fix?
2) when logging in or out I get error '127.0.0.1/\index.php' the "/\" can't find fix
3) in some of the show full size pages I get 2 download buttons have I done something wrong

[V@no]

1) dont know
2) maybe it only related to your local server?
3) the second download button is "zip download" its a future