What is it with the phpEd 4 text engine that causes custom fonts to display with really weird behavior?

Ok, now I know this is one of those things you could consider a minor annoyance, but I want to be able to use my custom fonts. Courier is just too nasty looking for me and I've grown accustomed to proggyfonts.com's fonts. I've been using them with Homesite 5.5, EditPad Pro, and putty for months now.

And this isn't with italic and bold styles - even if it were, I do not see why phpEd should behave any different than the 3 or 4 other programs that can use these fonts just fine. They are monospaced programmers fonts, and each character is designed to be the same size regardless of bold or italics or normal display.

I first noticed that any file I opened had extra spaces in it. But they weren't extra spaces, just whitespace that looked like extra spaces. But the interesting thing is it MOVES when you select lines and continue selecting things (I wish I could make a video of it). Makes the entire line shift and the non-space whitespace 'shifts' accordingly. Another thing that might help pinpoint the problem is that when I try to type out a new line, the cursor begins to get further and further away from the actual end of the line (where the last character appears) - as if the text engine thinks the font is wider than it actually is and keeps adding extra space to where it thinks the end of the text would be.

These fonts work fine in the terminal window interface. =)

I would really like to move on from the static world of homesite and get a real PHP IDE, and phpEd has been on my list for quite some time, and now with all the killer features I'm ready to make the switch, but now I'm forced to go back to courier new? Gross!

Here's some screenshots:

I found that unchecking "monospaced fonts" on the Appearance settings tab resolves the weird extra spacing at least.

So, if the problem gone away with unchecking "use monospaced fonts", it means that the font metrics vary depending on the style applied.
There is nothing wrong with PHPED. When "monospaced" checkbox is checked, IDE does not call system to get each character width, it just relies on the "monospace" property and thinks they all are of the same width. Certainly, when it outputs consequent characters of the same style and color, it does so at once and if font is not truly monospaced it may appear shorter or wider than pre-calculated width for these characters. That's why with such wrong fonts you may get extra spaces or overlapped characters.
It may not happen in other edititors if they do ignore if font is "monospaced" or not.
Solution: either select another font or uncheck "use monospaced font".