Well, what about using "comm" as proposed by Michael in the other mail? It seems to be part of coreutils and should be everywhere.
I guess that many people, including me, are not fluent in awk. So, I am slightly in favor of the "comm" approach ;-)
comm is definitely simpler and for some reason I forgot about the leading timestamps (again!) dismissing it thinking that the inputs weren't sorted. But luckily they are and if Naresh or anyone can confirm that comm is well supported in the BusyBox testing environment, then using that is fine w/me.
"comm" works in our environment.
- Naresh