Ok, EVERYBODY I know, and probably 99% of computer users set their monitor to go to the edges of the screen(I set mine for each resolution NOT to be skewed). When you do this on monitors a "circle" or a "square" selection in resolutions different from the aspect ratio of the monitor WILL appear skewed ON THE MONITOR....this has NO effect on output devices like printers and such. Somebody that calibrates their monitor for 1280x1024 and make a picture with perfect circles to them will have that picture appear with ovals to somebody who has 1280x1024 set up to "fill the screen". Then, somebody who "fills the screen" at 1280x1024 and makes a picture to have what look like perfect circles to them wil most likely have their picture look like it has "perfect circles" on most other peoples monitors because they are most likely also improperly set. This is actually an occasion where "two wrongs MAKE a right". I think it's a matter of who's looking too. One person may not be able to notice the skew(it's not THAT great a difference), while another can easily(I can and it bugs me). If you want an EXTREME example set your computer to a letterbox resolution(like 1280x720) and make it fill your entire screen(via your monitor controls so that there is no black surrounding the picture if you're not understanding what I say). Go to photoshop and make a 100x100 selection box and tell me that it looks like a square...if it does I want some of what you're smoking.
Here's my clever comment