hosts file not parsed at bootup

I have a laptop which I've loaded Win2k3 sp1. I have a 3Com PCMCIA network
adapter for use while in the office and I'm using the loopback adapter at
home. I disable the 3Com card at home and enable the loopback, while in the
office I disable the loopback and enable the 3Com. The reason I use the
loopback at home is because I do web development at home and IIS needs a
configured adapter that is connected to serve web pages. I then configure my
hosts file at home to match the dns names of the web sites that I'm working
on. However recently it seems that the OS isn't reading my hosts file at
bootup, or else it's flushing what it reads after bootup. I can't ping any
name in my hosts file which is something I've never seen before. I've
checked the obvious no period "." in the name of the file as well as spaces.
I've double checked...triple checked the names in the file. I've manually
flushed the dns cache hoping that would clear it up but nothing works. Event
viewer has no errors at all. Can anyone direct me to a TID that explains how
to troubleshoot this problem, I don't know where to start...should I be
looking at a startup log to make sure that the hosts file is getting read or
a registry setting that controls how the hosts file is found and parsed? I'm
at a loss here. thanks in advance.

Darin