Apple OS ridiculous about things like that :/
I just tried downloading firmware 4.3.3 for ipod touch 3rd gen ( i have a 3rd gen 8gb) and everytime i try to restore with the file it says not compatible with my ipod only 2nd gen firmware works with my ipod.
mm i jailbreakde mine with no problem i used redsnow i will recomend u to go here Jailbreak Iphone 4, 3 & 3gs | Jailbreak Ipod & Ipad too use at ur own risk idk if it has any virus or go to any other popular sources websites like pawncenter or go to jailbreakme.com heres the video for jailbreakme.com no pc needed
JailbreakMe 3.0
go to that site on your itouch safari, and its a automatic jailbreak