Originally Posted by
Frag_Maniac
Since Act 1 is very linear and you can't even explore very far without doing the story missions in it, I would assume it's more likely controls not responding as they should, or the now and then problem with the rope getting no clipped into the rock stopping you from ascending any further. I don't know which climbing problem was addressed, but I do recall the staff saying there was a glitch in the climbing that was being worked on in one of the patches released.
As for the locations, there's also one just north of the one at the bottom of the river that remains on the map. You can still get 100% completion without them though, because locations aren't part of completion. Most every patch version has included more significant fixes they were working on, but patch 1.4 was rather light duty, making it feel like they were at times glossing over things that were mentioned a lot.