I've come across a rendering problem in the SE text editor when using combining diacritics in IPA notations, e.g. U+032F: 'au̯' and U+035C: 'a͜u' (German diphthongs). Several glyphs overlap making the word unreadable. This is happening on Mac OS X 10.7 with Safari 6 and Chrome 26, but not so in Firefox. I'm using IPA Palette version 2.1.1 by Brian Hall to input IPA symbols:
Looking at the CSS font stack used by the editor, I see that the second font after 'Droid Sans Mono' is Consolas. I tested Consolas (version 5.22) on my local text editor TextEdit, and the overlapping problem occurs here as well in Rich Text mode (TextEdit), but not so in plain text mode. Also, when using the font Menlo (third position in the stack), no problem occurs:
I don't understand the exact underlying problem, but I believe it's some complicated stuff related to both, the font Consolas and the way browsers work with language scripts or something – in Firefox, everything is fine. When I deactivate the font Consolas on my system, everything is fine in Safari/Chrome, too…
My suggestion is now to simply remove Consolas from the text editor's font stack, or at least place it to the last position. This should circumvent the problem. (That Droid Sans Mono, which I believe to be a web font, doesn't work in the first place is probably another story…)
(If anyone else wants to check if this problem occurs on their machine, just click Edit on this question and see if there's overlapping in the IPA in the first paragraph.)
Oh, and another user reports that Chrome (Win or Linux) doesn't render the IPA correctly when these diacritics are used (other IPA renders OK), which is probably a different thing related to Chrome itself.
(Refer to this question at the German Language SE: Phonetic help for 'Frobenius')
ADDITION: Telling from the feedback, the Problem seems to occur only in OS X with the font Consolas. Now, in OS X, Consolas is not pre-installed; it is only installed with MS Office. Simply switching places with Menlo in the CSS font stack should be a simple but effective workaround (Menlo before Consolas) – doesn't change anything for Win or Linux users (Menlo is OS X only), but avoids the problem for OS X users who happen to have Consolas installed via MS Office.