I had the same problems with the ING site.
Asked ING in an email if they changed anything at their end, but the could not help me and suggested that I call a payed support number.
Did not want to do that so tried several things in 12.16 like masking or other tricks and it made no difference.
Tried Opera 17 quickly and it worked, but I do not like the new version at all.
Decided to downgraded this weekend and 12.14 is the newest version still working.
I susspect that somthing has changed in 12.15 and 12.16 but have no idea what it could be...
I know some people prefer to use the older 11.64, but because we are dealing with a banking site, using 12.14 seems the safer thing to do.