I'm now using 12.6.1033 of RST drivers, i had tried re-installing v11 and v10 with no luck either).
Here was my resolution:
Interesting, that fonts were issue for you, Welby. after 2 days of trying uninstalls/and re-installs I never could hit on the conflict. But your debug sparked something in my memory.. One tool i used before was microsoft sysinternals suite, in particular, procmon. And discovered when the IASTORUI.EXE goes belly up it was reading registry for file associations.. in particular .png. (why it needs that i don't know). I recall another microsoft application Calc.exe (the common calculator) also has a weird display issue/related type bug when it reads registry there in the file associations. And Sure enough, uninstalling FastPicture Viewer (which googling also showed other users were having issues) resolves the problem (for me at least).