I have two Unos, an older unit and a R3. I use the USB ports on the front of my win 7, 32 bit computer. The old Uno shows up in device manager as "Communication Port (COM8)", the R3 shows as "Arduino Uno (COM12)".
If I use Arduino 1.05 they both compile and upload.
If I use Arduino 0022 they both don't work ((avrdude: stk500_getsync(): not in sync: resp=0x00))
I have sketches that will compile in 1.05 but not upload. They compile in 0022 but it won't upload.
I have spent many hours searching for a solution but I am about to give up.