Lines appearing at top of bitmaps with transparency

Something that totally trashes Aero for me is the appearance of very fine lines at top edge of bitmaps where there's transparency.  No, it's not a rogue line of pixels with colour values, they're totally transparent. Have even been into images and cropped down, to be absolutely sure.  These lines appear both in pngs and also using photoshop (been using photoshop for 25+ years, so there's no error here!).  Makes me question why I subscribe to Adobe Cloud really, because if Aero's no good, won't need the cloud thingy.

What really sours the Adobe experience is their tech support which to be honest I dread engaging with because there's and underlying element of sabotage built-in.  What do I mean by this, well, you ask a serious question, they tell you to reboot your applications, or as one support said, he wanted me to open a .jpg.  I explained that .jpgs don't have transparency option which he should have known!  He then proceeded to do the pretend and well acted-out 'Im having a problem with hearing you', before then hanging up.  This isn't the first time I've had this type of experience, but many, many, particularly with issues I was having with Adobe's Indesign Publish Online, which went on for about 8 months.  Makes you lose the will to live.  Does Adobe really know what's going on with their tech support I wonder - NO