I use Pidgin to chat with my YM and GTalk friends. Usually, when I am signed into my Gmail account and I'm also connected to Pidgin, I receive my messages in both my browser-integrated Gtalk window and in my Pidgin window in the same time. And when I reply, my answer appears in both places in the same time.
But today, when I checked on my mail account I have noticed an offline message from one of my friends. The message was 4 dais old. The strange thing is that in all these days I did opened my Pidgin app, so I should receive that offline message till now. Strangely, I didn't. Furthermore, when I checked my friend's conversation log file in Pidgin, there was no trace of his words! So, the only logical conclusion is that, somehow, and for reasons that are beyond my understanding, my Pidgin account did not "pulled out" the offline messages from gtalk. Sort to speak, they did not synchronized.
So, I imagine I'm not the first person who encountered this problem. I would like to know what caused it, how an I prevent in the future and how can I keep the conversation synchronized and keep them safe?