Wow, it is amazing what advice you can find in these forums!
I was having the same sort of problem.
I have a Tenda W311U USB wireless dongle that I have been using for some
time with 32-bit PCLinuxOS. When I cut over to 64-bit the
wireless connection would drop all the time. Very annoying!
I also have a Realtek micro wireless USB dongle that I got
drivers Linux drivers for, but could never get it to work.
The solution was to blacklist the built-in rtl8192cu driver
and let the newer, vendor supplied 8192cu driver load!
Don't know why rtl8192cu did not work, but then again
now I don't really care.
The Realtek with 8192cu works a treat and has not dropped
once in 2-3 days. Needless to say the Tenda has been retired.
Many thanks to all!