I wonder if its your display / touch panel acting up?
I was noticing my phone would be in all kinds of weird areas / settings / apps whenever I pulled it out
of my work bag and/or pocket. It was also getting quite a bit of dust under the screen near the
sd card slot area. I bought a replacement screen off e-bay. The thing was new! Still had the stickers
on the buttons. It was the front half of the phone, touch screen plus LCD display underneath.
Finally had time to replace it this weekend, and since its got a new screen, haven't seen any of those
weird issues so far. I kept the old touch screen/LCD so will try and split those apart and clean out the
dust and maybe put it back in later, see if the dust was causing the touch issues.
Not a bad fix for $15!