/dev/sda3 won't let me access

[knp]

Greetings Feepilz
1°)- I am not an expert but an "almost-novice".
2°)- EXT2 File System has never worked ALONE for me when the goal was to INSTALL
"French_Knoppix 5.1.1_live_DVD" on the appropriate HardDisk partition
3°)- If you have the same goal or a similar one with a "Knoppix_live_CD/DVD" a probable good way is to test this one:
a)- run a console with administrator privilege
b)- run "knoppix-installer"
c)- choose your automatically proposed "Ext2_preformatted_sda3"
d)- let the "installer program" do all itself automatically on your "sda3"
f)- especially let it transform your "EXT2_FS" into "REISER_FS".
All these points concern a "DEBIAN" package.

Your "POST" is dated on 2011_nov_or_dec...
Perhaps have you found already a solution to your problem before my reply?
Greetings