The lever for the drain stop on the sink corroded so I elected to replace the whole assembly. Now I wish I had only replaced the lever... (I attached jpg files - couldn't figure out how to insert pictures). Problems: 1) I now have a leak where the assembly butts up against the bottom of the sink. I used plumbers putty under the flange on the lip of the assembly. The water seems to be going into two holes at the top of the drain and then getting into a void space and then getting by the ring and nut just under the sink. Any ideas on how to stop this leak? 2) There is also a leak where the plastic replacement assembly meets the metal trap assembly. I suspect that part of my problem is that the drain goes from PVC to metal to plastic. Note that the PVC has several angle transitions in it. It sticks out from the wall about 7". Should I cut it back and go to all PVC? Or should I transition to metal? Note that the wife wants to have a pedastal sink installed in place of this one in the next few years, so I don't want to spend a lot of money on this sink, but then again it would be nice to not have it leaking Thanks in advance.