Today, I realize a security bug of Skype in Window Phone 8 [LUMIA 520]. The bug is described in the following:
Last month, I left a group in Skype, then I didn't recieved message from this group when I logged in Skype in my laptop and my LUMIA 520 mobile. Skype was working correctly.
However, from last week to now, there is a strange issue that I can still receive message from this group when I log in Skype on my LUMIA 520 mobile and my LUMIA connects to a wifi access point which other memebers in this group are using for their devices (laptop, mobile) at my office.
But this issue is stopped I can't recieve message from this group when I connect to another wifi access point at my home. I think that it's a bug of Skype in Window Phone 8.