I got this rather annoying problem. When somebody sends me a message while I'm offline, I only get those messages when I send a message to that person myself.
I remember experiencing heavy delays in those kinds of situations when using Skype for Windows, but the messages still were delivered all by themselves, no need to send a message to somebody to check whether he/she has sent you a message while you were offline.
This issue is not specific to Skype 1.4, it was the same in the last stable version.