Keyless entry, revisited

The keyless entry to my 2000 Venture worked okay, I had to be very close for it to work so I replaced the battery. Now the door lock button doesn't work and neither does the power door. Only the unlock button and then again I have to be standing almost on top of the van for it to work. I replaced the battery again in case I had a dud and it's not any better. I have used the manual to reprogram the remote. Nothing works! I did not touch any of the circuitry when I replaced the battery, I was very careful. Do I have the right sized battery? Any other suggestions?