No. There should be a gasket for the lid opening. If it's there, keg lube should help it seal. If that still doesn't work, or if you don't have keg lube, stick a penny under one or both of the lid feet to increase the pressure.
Do you have them pressurized? They will definitely leak when they aren't pressurized. The pressure forces the lid up into the seat, putting pressure on the o ring. Without pressure, the o ring won't be fully seated and doing its job.
yes....that is totally normal...assuming you did not pressurize the keg first. the keg will get a complete seal when you hit it with C02....if not, water will escape. trust me.
My latest keg had a flat o-ring that leaked. I changed it to the fat round type and added lube and it doesn't leak even with no pressure. At morebeer the o-ring kit is about $3.