First i must say i use FL10 so those options might not be available in previous/later versions.
I don't know anything about 32/64 bits, just that it causes issues. :D I let the experts discuss in details.
For example, FL10 works in 32bits and some plugins are 64 bits only.
It causes issues/freezes, if you use them directly into fruity loops, so a workaround is to use bridged mode.
It's in the wrapping options (the wheel on the topleft corner of any vst/vsti window).
It starts the plugin outside of fl studio and then links it. It doesn't work all the time and when it does, it's still buggy^^
Better than nothing.
Most of the time plugins come in 32 and 64bits anyway so they work on any system.
Being curious, i downloaded the demo of fabfilter Q (nice plugin BTW) and installed the 32 and 64 bits versions.
I can only use the 32bit one. Otherwise it doesn't freeze my computer, but it cut the sound completely.
Wow that's hype; an new "Allcut" filter! XD