1) & 2) I don't think you have anything to worry.
3) Unfortunately, can't tell why Bitdefender didn't spot the culprit. However, as I have said to many people earlier, there's not protection software that would detect all possible threats. Some detect something that some other doesn't and vice versa.
4) Did you see those items on on 12/22/2008? Bad items may fake their creation dates.
5) Without knowing whole thing it's not possible to say if there was connection between those two things or not.
3) Unfortunately, can't tell why Bitdefender didn't spot the culprit. However, as I have said to many people earlier, there's not protection software that would detect all possible threats. Some detect something that some other doesn't and vice versa.
4) Did you see those items on on 12/22/2008? Bad items may fake their creation dates.
5) Without knowing whole thing it's not possible to say if there was connection between those two things or not.