Please help!!! cant stop oil leak

I really need some advice as to what my next step should be. Here are the symptoms for my 2001 range rover SE 4.6 Bosch engine:

The valve covers were leaking a little so I replaced the valve cover gaskets and had no problems on the way to work the next day. Then on the way home that night I heard something hitting the fan blades. I open the hood and there was oil everywhere and that is what was splashing on the fan. So I pulled the engine down to the valley pan and found that both ends of the valley pan were leaking. Also the pan was bowed up in the middle. I ordered a new valley (belly) pan and also got the rubber gaskets at each end of the pan. The new pan was flat in the middle with no bulge. I used red high heat liquid gasket all over the valley pan connections and on the end gaskets just to make sure that there would be no leak. I buttoned it up and ran it for about 30 minutes around town.

After only 30 minutes I got out and saw oil dripping down the back of the engine. I then pulled the engine back down to the valley pan and found that it was bowed up in the middle just like the old one was and that the oil was now leaking out of only the rear end gasket on the valley pan. I have no doubt that this is the problem area but I don't know where to go from here. It is obvious that the oil pressure is too high and the oil is leaking out of the easiest place it can find. Is there a relief valve that may be clogged or stuck? does any have any suggestions or has this happened to you?

Thanks
Ryan

I am not sure if anyone might care but I think I fixed the leak. Just in case this happens to you I think I found out what the problem was.

After researching it a little more I decided that the problem was either the oil pressure relief valve in the oil pump or the PCV system. On the PCV system I looked last night and one hose had a kink in it and also the oil separator appeared to be clogged up a little. I cleaned the separator and straightened out the hoses. Also for good measure I pulled the oil filter and once you do that you can see the middle of the spring on the oil pressure relief valve. I used a flat head screw driver and moved it back and forth to make sure it was not stuck.

So fingers crossed that seems to have fixed the leak in the valley pan.