That may be a valid explanation. That though is very, very specific.
"Plugins written in 32-bit specific delphi ..."
The vast, vast majority of plugins will be written in c++ and if certain rules were followed regarding the language and data structure, interfaces and so forth very few if any problems should have been met.
I've decided to install both 32 & 64 bit Win 7 partitions (along side my long serving XP partition) - mainly because my (t)rusty old sw1000/plugstation system is still used & will work on the 32 bit partition (but not 64 bit).
If God did exist (and he doesn't) he would answer to the name of Maurizio