every level has a certain amount of lil sisters... u kinda need to harvest/rescue all of them to get the as many adam u need for upgrades.

Don't be too sure . Only good against nitro splicers or BD proximity bomb . During early game it's nice.. Onto mid or late game i hardly even required using it unless for grabbing unreachable stuffs . I would say electrobolt or winter blast FTW 

ive started encountering crashes too... when i played the first round it was fine... started playing second round it was still fine....

but after i installed the UT3 demo... thats when it all started. now i constantly have to save the game just so that i dont lose anything

not sure if its coincidence or the UT3 demo is screwing up the game.

Same goes to me.
Played the game until the finish for 2 days without turning off the PC when i stop playing the game and save for a while didnot face any crashes at all.

Oh, i'm using 2900XT kerosfire with dual 24" Widescreen game on 1600X1200 resolution with Catalyst 7.10 by the way