Oh my god... I just registered for Matmid earlier this month when I flew LY to Israel. Finally got the email with my account login details today, so I logged in with the temporary password they sent me to create a permanent one. Crappy website, but fine - it worked.
Buuuutttt... trying to add the flights I recently took was a clown show. It asks you for origin/destination, flight numbers, etc. - fine. But at the bottom it also asks for the ticket number and "order number" (which, the helpful info icon tells me, is "six digits or numbers" - I assume it's the record locator.) So I input all that info and click "add a missing flight" - and the site just goes into hang mode, with the spinning circle of interminable death. Several repeated attempts and trial and error later, I realize that inputting the ticket number and record locator is to blame. If I leave that info out, then it accepts the flight info, and the flights show up under the "submitted for updating" link. Of course, we'll see when/if those flights do get credited.
Was this website done in 2002 by a group of high school students for a final class project? Unbelievable.