I had some php running in an account on unix.uvic.ca which called a mysql database running on mysqldev.tapor.uvic.ca. the mysql_connect call failed. By moving the php to an account on lettuce.tapor.uvic.ca, the mysql_connect call succeeded. In investigating this, I also discovered (with help of Greg and Martin) that the db username I was using was corrupted somehow, which obviously compounded the problems. We created a new user, and that username worked fine from lettuce, but not from unix.uvic.