networking - Why won't my DHCP addresses "stick"?

I've been having some addressing issues that I've been unable to solve, and I'm hoping I can get some guidance about other things to research.

Service provider is Time Warner cable. A static IP is configured for connection to their headend. My gateway is set to 192.168.1.1, with a subnet mask of 255.255.255.0.

I'm using a Netgear WNR2000 wireless N router. Between the family's i*Devices, smart TVs/Roku Boxes and laptops, there's probably about two dozen IP addresses that need to be assigned. Everything is within 30 feet of the router, with a maximum of two walls between the router and the device, so I don't think it's a lost signal/interference issue. When I initially set up the router, I had set up DHCP to dynamically assign from a pool ranging from 192.168.1.101 - 191.168.1.200 as my DHCP server range, and for about six months, everything seemed to be working fine.

Then, I started getting sporadic IP conflict messages when I would plug in a new device. I'd come home from work, fire up my laptop and get an IP conflict. Or suddenly Netflix refused to load. Or the MacBook Pro couldn't get an IP address assigned to it. At that point, I inventoried every device and assigned static IPs for every MAC address I could find in the household, and set up specific address reservations for specific MAC addresses, still using the router as a DHCP server. I have opened up my router to assign IP addresses in the 2-254 range; everything I'm specifically reserving is in the 101-200 range. My primary computer from which I'm doing all the tweaking is running Win7 Home Premium 64bit. I've found the Home Premium version to be a little lacking in network controls....

That seemed to work well for a while, but within the past month, here's the symptoms I'm experiencing.

1.) I have an HP wireless printer, and it's assigned to 192.168.1.120 in the DCHP reservation table. No matter how many times I power off/power on the printer and router, I cannot connect to the printer from any device, and the list of "connected devices" on the router tells me it's on 169.254... The last two octets change; though I've not been able to diagnose how often or if it's tied to router resets or some sort of time schedule.

2.) I have a Samsung BluRay player that I set up around Christmas, and assigned to 192.168.1.136. ~Sporadically~, this will stop seeing the network, and when I check router settings, it's been set to 169.254... Two different octets, which are also different from the HP printer subnet.

3.) I have a Lenovo IDx NAS Device that was working perfectly since September. Last night, I was unable to access it through Windows Explorer. I have it assigned to 192.168.1.118, and the "connected devices" panel says it's on 192.168.1.8. When I try keying \server\share into explorer, I get a note that the NAS device can't be accessed because it's on a different subnet. And yes, I verified that my subnet mask is still 255.255.255.0. I cannot get this device to take its assigned IP address.

4.) Curiously, if I use Lenovo's proprietary software interface to the device, half the time when I launch it I can access everything, half the time I get a message that's it's either "unavailable" or in a different subnet. Even more curious, the network drive I have mapped to one of the NAS shares works just perfect through Windows Explorer, which finds the resource and allows read-write access.

5.) In the past couple weeks, if I'm connected and leave the house with my laptop, the wireless card on my laptop cannot get an IP address unless I reboot after my return. No amount of ipconfig/release/renew or turn the adapter off/on action fixes that problem.

So. WTF. I know enough about networking to be dangerous, not enough to know where to start diagnosing this issue beyond what I've tried above.

From everything I've tried, I suspect it's a router issue. But it also seems as if there may be an issue with how DHCP leases are assigned and revoked and re-assigned, and there may be some router setting I don't know to look for. Router firmware is current as of last night when I spent a couple hours googling and messing about...but could there be some other odd hardware issue? Before I bite the bullet and get a new router to test, I want to make sure I've exhausted all the possible software solutions.