Simply put:
6/8 people have locks 1 through 4 in Normal Mode
2/8 people have no locks
We can all enter Normal Mode together, but if we set it to HM: we still see the speeder bike and can ride to Soa. However, we CANNOT get a full, fresh instance in hard mode.
To make matters worse:
If we create a 6man raid, go in in Hard Mode and then invite the 2 guildies, they can enter but can't see us.
They CAN, however, see us on the minimap AND they have the speeder that we would have had if it were Normal Mode.
Nice bug?