QUOTE (MySummerJob @ Feb 26 2008, 09:13 PM)

What is trend micro? and no it doesn't affect my aim or msn, so it must just be firefox, and that is what I came here for =/.
So Firefox is deleting your cookies eh?
Mine does this as well even though I have set it not to... It's a slight inconvenience but I never really checked it out and just always thought it was a bug.
Possible reasons aside from a bug include
1: Someone clearing the cookies on your computer (i.e. brother looking at porn, parents etc.)
2: Cookies expired or window performing maintenance and clearing out your temporary internet files folder.
If it is a major inconvenience and neither of the reasons above are what's responsible I suggest going to the Mozilla site and asking them about it or browsing their forums. Or you can have it set to clear your cookies once a month (recommended to keep Firefox running smooth)
There are anti-virus/anti spy,ad ware programs that may be messing up your Firefox as well. Could be any number of problems really.