Photoshop itself is and always has been very robust, but Bridge gets persnickety sometimes, reporting low memory or just hanging, and when it hangs it really hangs... Today it was not responding and so I went into Task Manager (Win 7 Pro 64 bit) to end the process. I noticed that is is listed as a 32 bit program (Photoshop.exe is not). Is this normal? Seems strange to me.
Yes. Bridge is still 32bit to provide maximum compatibility to other programs that use it (which extends far beyond PS).
Oops. Just saw the "CS5" bit. Sorry, yes, 32-bit. Only 64-bit in CS6.