Frankly, all mentions of "DPI" in the POF image instructions and help files are wrong, and I can see that this has led to a lot of confusion. Whoever wrote the instructions confused "DPI" (dots per inch, a measure of pixel density) with simply the number of pixels as a linear measure of size. For example, one section of the text of [url=http://www.plentyoffish.com/faq.aspx#17]Images Help[/url] reads as follows:
The largest size a pic on your Profile can be displayed at in your Browser is 300 Pixels wide by 299 Pixels high. Simply make sure that the Height of your Image is 1 Pixel less than its Width, such as 300 x 299, 600 x 599, 789 x 788, 1,153 x 1,152, etc. ... or any other Size you like, but not exceeding 1,200 DPI on any one Side. After upload, if you then click on that Profile Thumbnail Image placeheld as the Main Pic, then check the Properties Page, your Image(s) should read 300 by 300 DPI. The Thumbnail "Mouseover" pop-up Image will also be displayed at same Size. 1,200 x 1,199 DPI BMPs will give the very best Results, but sometimes these Images will not upload at all because they well exceed 4 MBs.
Every instance of "DPI" in the above passage is incorrect and confusing, and should be replaced with "pixels".
Of course, even if this error is fixed, the text is still horribly written, but I guess that's a whole different issue.