CandyFold does not apply the extra vertical line spacing : the indent lines go N pixels too down, so that they "overwrite" the following line. See screen shot in attachment : the indent guides overwrite the dot of the "i"s (the screen shot shows also the core bug #3414877 with current line highlithing (which is also a bit too down) & the red caret artifacts left when moving the caret).
I'm using updater on "current branch" : jEdit current 5.0pre1 - Installed version: 2012-06-08_12-01-50. CandyFold 1.1.2, on a WinXP, anv Sun JVM 1.6.0_22.
I is not a big deal, but rather annoying though. If you want me to make some tests, I'm willing to help.