Hmmm, it should be theoretically possible to fix your second note - it is also something that happened to me a few times when I scrolled very long pages from awkward positions (i.e. lying in bed :-P). However, since the latest release, with the introduction of the feedback bar telling you how far you are from a jump, involontary jumps can be easily avoided. The size of the feedback bar can be customized in the settings, and I personally have it all the way up to the max size - that helps alot. However I think it shouldn't be a big deal to measure how far the vertical scroll is with respect to the horizontal one, and avoid jumping if the vertical scroll is bigger. Thanks for the feedback.

With respect to the first issue you're mentioning, that I realize seems to be much worse, I have to run some tests because I never had a similar problem.