Connect D-Link router as AP to static IP network?

I have a small network issue.

The house we live in is not kind to wireless networking (3-storey reinforced concrete frame)
and whole family is having issues with iPhones, iPads, laptops etc. To complicate it even more I work from home and have various production systems and servers that need static IP address system to work properly.

I have 2 routers. One D-Link DIR-615 and a D-Link DIR-635.By setting them in each end of my house every one have perfect connection to the routers except that I can't setup the AP (D635) to connect to internet. The Router IP (D615) is set to 192.168.0.1 and the AP (D635) is set to 192.168.0.2.

Because of the static IP network I guess it is the IP, SUB, GW and DNS settings in the AP D635 Internet setup that I need to figure out. I suppose the default Gateway should be the router D615 IP 192.168.0.1? I tried a bunch guessed settings but got errors like "WAN subnet conflicts with LAN subnet".
I can get it to work if I set the router to DHCP and if following guides to set up the D615 as access point I found on Internet and in the manual but when I try to configure it to work in a static network it will I fail miserable.

I'm no network genius so if some smart person out there could hint me in any direction here I would be really happy.

Added (1). SOLVED!

I did solve this self. It was my low level "know how" that caused me headache.
Your kind suggestion Dallas/Chris was not an option sorry to say but thank you.

Because my lack of know how I thought I hade to deactivate the DHCP Server Setting under Setup in the D-Link DIR-615 router to have all these static IP machinery working on my network. This seams to not be the case. By enabling the DHCP Server feature in the router and set the Internet/WAN setting in the access point DIR-635 to dynamic instead of static it all seams to work like a charm. Just finished testing the print & press machinery RIP'ers, FTP-, mail- and web servers etc etc and it all communicates internally and externally just fine. I have 225-275 Mbit/s wireless transfer speed where ever in the house and never fewer than 3 out of 5 points' connection strength in any corner of my house. I hope this is a reliable solution though.

Should I delete this question when solved? Solution was pretty sim

That is a heavy question. I would wonder about the service in your area and possily using one the phones as a hot spot and use it instead of your regular internet provider; xox Mac heh heh Not sure if Dallas is much help but it popped up on my page:-)