I have some sympathy with what's in this thread. I've never understood getting a message saying OLCI is open when it isn't.
However BA.com is paradise compared with my attempts to MMB on Singaporeair.com. That really is a joke site. If you finally get it recognize a booking, you more often end up on a 500 error page (no user-friendly explanation). I've tried with 3 different browsers but all end up in the same black hole.