I'm very near the end of the game and am stuck in two ways:

1) When I enter the Mother's chamber, there are no wall seals and the ankh is not present. I've used all of the mantras in the correct areas and possess all four seals, the powered-up grail and key sword, and the medicine. Is there any other condition that needs to be fulfilled in order to awaken her?

2) For the purposes of accessing the Hell's Temple side quest, you're supposed to go to the second screen of the waterfall after speaking with Dracuet and sleeping until night falls and enter a hidden room to the left of the tent. When I go there, there's no apparent way to enter this room. I've tried moving all the way left, moving left in one-step increments and pressing up, doing the same and pressing up while jumping, using weapons, throwing bombs, etc., all to no avail.

My game is patched to the latest version.

Edit: Figured out the solution to the first problem. Apparently there's a dais I missed near the top of the Shrine of the Mother that causes the seals to appear in her room. Still no progress on the second, though.

In case you are still wondering, you sleep in front of the Elder Xelpud statue, then speak to the Elder, then go the secret waterfall room. It sounds like your confusion comes from using guides.