D-Link DIR-655 :: Horrible Connection Quality And Regular Disconnects

I tried multiple times to register a username here and no matter what I chose I would only get "An Error Has Occurred" when I submit the info. I've tried this over several days and keep getting the same dead end. So, I went to bugmenot.com and I'm using a generic username that was given there in order to post this. So...there's that...   

Starter info... I'm running Hardware Rev A4 of the DIR-655 on the 1.33NA firmware. I never upgraded past that firmware because of all the horror stories I'd read about new firmware here. Up until lately it's been fairly stable. The issues I refer to SEEM to coincide with my recent installation of Apple TV hardware on my wireless network, though I can't confirm. It's never been great with this router, so that could be coincidental. On my network I have a hardwired Mac Mini, wireless Macbook Pro, a hardwired D-Link DNS-321 NAS box, Apple TV, Logitech Revue, iPad, iPod Touch, iPhone and occasionally one each of a Samsung and LG Bluray player (only when they're powered up, which is rarely). I'm also using a wireless repeater in the middle of my house because the DIR-655 doesn't yield a very usable signal in my master bedroom, which is on the opposite side of the house as the router.

With all that being said... I have had terrible issues being able to keep a steady connection wirelessly with this router as of late. Streaming Youtube videos will stop after a few seconds, loading websites will just stop responding all together, and I can't even keep a connection to stream music from my Mac Mini to my phone or AppleTV using Home Sharing in iTunes. I'll get a few seconds of a song and it will just drop out completely. It's been extremely annoying and I'm ready to take a hammer to this router, to be honest.

I've checked my logs and there were all kinds of FIN:ACK, PSH:ACK and SYN:ACK TCP packets that are being blocked. I noticed many of them were coming from Apple IP addresses, so I assume that the AppleTV had a lot to do with those. I actually used the Inbound Filter settings to allow requests from a whole block of Apple IP's, which seems to have settled log items from them down a lot. There are still quite a few that seem to be coming from Google IP addresses (I presume the Logitech Revue since it uses the Google TV interface?), but the Google IP's are too random to go allowing a large block. [code]

I have Advanced DNS disabled. All Traffic Shaping and QoS boxes are checked to enable. Comcast is my cable internet provider. I've noticed that my WAN Connection Up Time is often a fairly low number like the connection to the cable modem drops out frequently.