Iphone jailbreaking for 4.3.3 with week 44 bootrom?

I have a 3Gs running on ios 4.3.3, I want to jailbreak it using redsnow however when I load redsnow it asks if the phone was manufactured between weeks 40 - 45, mine is a Week 44 going by the serial number. Does this mean I cannot jailbreak the phone without it being tethered or can I jailbreak it at all? When you run resnow it says for weeks 40 - 45 results vary, what does this mean?