Oddly you state what does work and what does not,
It's a real problem with the 64 bit version of ie9 and ie8 for that matter,
Just because microsoft included a 64 bit version does not mean every website on the net will incorporate it,
Use what works,
Feel lucky that flash works in ie9 32 bit without disabling gpu rendering in advanced settings.
All active x content goes through the xss filter, disable this new filtering process and things actually work,
xss filter is on the security section, custom level near the bottom of the list.