>Only thing I can think of is that they track your IP and won't send the history if you have two instances from the same IP address. But I don't quite get why they would do that.
That is not the case.there is something funny going on with his/her client. I use ircloud for past 6 month and it is excellent.I always use it from home which is basically a one ip address shared between 4,5 device.and I always can load my message from different devices.