Thanks jbeck, for trying another ISP and clearing that up.
Also, after reading ycvw's post, I tried and managed to play the game perfectly from 4am ( GMT +8 ) this morning. Since I haven't played it in so long, I put in a few good hours until the problem started again, no different to what ycvw experienced. Tried mutliple times since then and definitely back to the same issue, consistently ( until 4am tomorrow? - personally not going to check that again, but if anyone wants to finish the weekend challenge you might want to ).
Anyway, based on this info, I find it highly unlikely that two totally different ISPs ( and one being ADSL, and one 3/4G ) have the same problem with one particular game at certain times of day.
I'm convinced that it's not our ISP, Router, Firewall, Anti-Virus, Origin / ME3 Installation or anything at our end that EA's support is routinely telling us to check. It doesn't even sound like our accounts' DLC entitlements are an issue either after today's experience ( which seems to be the most commonly discussed solution ).
I've noticed as well that a few times instead of actually logging in, I get the 'Redeem Online Pass' message instead. Its only happened a few times so far and disappears on restarting the game, but the last time that happened it was something to do with a server problem, so I'm also thinking its not something on our end.
