Shouldn't, no. It's the Automatic UPlink that has this limiation on 2Mb UP link speeds. If Manual is set, the router should work at the higher up link speed.
I'm right on the board with this one as I'm at 2Mb on my ISP and they don't offer anything faster.
I do know that the newer DIR series routers from the 645, and the newer L series routers have higher preset UP link settings unlike the older routers. I guess at the time, there wasn't any or maybe there way some forethought about Automatic UP link speeds since at the that time, average users only has about that much from there ISPs. Now everyone is going well beyond that and not sure if DLink thought about that or not. There is some debate on if the cap is really needed or not. Over all, for those that have more than 2Mb or and higher UP link speeds, and your using a older generation router, disable Automatic UP link if users are seeing problems.
I'll update the stickies this weekend. Raining here so not much to do beside do some gaming.