I know what you mean I also thought the same thing about myself
I had never done a lot of hard road pounding running until 6 months ago
but i would have considered myself as quite fit
and only when I started to run on the road I started to get them
but after 1 month they seem to get less and less until the pain was gone

hey mate
i have just recentley gone through the same thing
i leave in six weeks time
i hve had the trip planed for about 1 year and after visiting nearly every camping shop in perth
i eventualy purchaced a black wolf pack http://www.blackwolf.com.au/rucksacks/bugaboo/
from what im told this pack won best pack for hiking the kokoda trail in 2007
i have done alot of training with the pac and so far and it seems to have come up with the goods
hope this helps
check out the link i have inserted there are many to choose from