Oil Pan Gasket change and still leaks

Hi everyone. I have a 2005 Pontiac Montana SV6 with the 3.5L engine. I observed the underside of the engine very carefully and concluded that my oil pan was leaking. So I changed it. I worked on it for quite a while. I bought the correct Felpro oil pan gasket, cleaned all the surfaces and got the job done. It took me two days. I noticed on the Autozone repairhelp site the picture I've attached.

Towards the back side of the oil pan, the gasket sorta takes a sharp 90 degree turn from going up to going horizontal along the block. There is a corner that I thought might need sealant, and so I put RTV in both sides, but I'll admit that I didn't put very much in there.
Anyway, it is still leaking about a drop per hour. After sitting all night, it has an unacceptable amount of oil on the ground. I have gone under there and examined it closely and know that it is coming from the oil pan gasket on the back side where I had to deal with the RTV.
My question is, what did I do wrong? I don't want to lead the witness here, but my theory is I did not put enough RTV in that corner. I also started and ran the car after only a few hours of putting the pan up and am wondering if my RTV did not cure in time. It was the black RTV by permatex. I think I will be doing this job over again and want to make sure I do it right. Any suggestions? Thanks.

Not sure on the Montana's, but many many cars don't even have a gasket from the manufacturer. They just have RTV and the Felpro gasket has been shown to do more harm than good when it comes to the oil pan.

Another issue is what kind of sealant did you use? Did you follow the directions to the tee? Many of the sealants you can't tighten right away or else it will definitely leak. Many you have to finger tighten the bolts and let it set for a period of time before you actually tighten to spec.