The PL framework shold work with any updated browser, but it is not flawless in IE9.
I have two (three) issues within IE9. Take a look with your own browser to see them.
The first one, and the most serious, is.
The second is image-resizing in normal text widgets (see the footer). For some reason, they are not resized in IE, which cause them to look a bit odd.
The third may be related to the Events Manager plugin, though I don't have the issue with TwentyTwelve. For some reason the first event in the Events Manager widget looks different from the rest. Only a minor thing, but I'd like to have it fixed.
Any suggestions for how to fix them? I guess some CSS could fix the two issues above, though for the first issue, it is a bug in PL.