Sorry, missed your posting. I use an iPad at home and surf using wifi and this is OK. There is some discussion on this and apparently, it has to do with the telco adding in an extra cookie that interferes with the login. Not much one can do though.
I guess the reason you missed my posting is due its failure to notify you? Strangely, unlike other replies that members posted, I was not notified of the above reply you posted.
Ok, after reading the link you provided, what I did was in my iPad, I opened "Settings", selected "Safari", selected "Block Cookies", then selected "Never" and the problem was solved.
I can now login my Pertama account via Safari on my iPad using Wifi. But I have not tried using mobile broadband. And I do not know if I will experience the intermittent auto login/logout problem as mentioned by other users of the same platform.