D-Link DIR-655 :: Need To Block Certain IP Address To Be Accessed By All Computers

Bought DIR-655 from Amazon. Rev. B. Come with 2.00NA firmware. Updated to latest one, and there are a lot of problems, to most of them, I was not able find any solution. Here they start:

1. WIFI SPEED PROBLEMS.No matter what speed, parameters, channel, mode, etc I select, router keeps working on 20mhz channel width. So I never get speeds above 65 mbit. In absolutely same conditions, my DIR-300 B1 (with DD-WRT firmware) gives me stable 150mbit. SO I KINDLY ASK, MAYBE THERE IS A WAY TO FORCE "40 MHZ ONLY" OPTION?

2. PASSWORD PROBLEMS.Router came with no admin password, I enter new password, hit "update" it says - wait 20 sec, after that, login page is displayed, but, new pasword does not works! since it asks again for empty password!

3. FILTERING PROBLEMS.I need to block certain IP address to be accesed by all my computers. Say this is 111.111.111.111 . So I added inbound filter rule, to block access to that IP. It does not works - IP is still accesible.

4. MORE FILTERING PROBLEMS.Since above mentioned method does not works, I have to use "ACCESS CONTROL" feature. It does works, but it causes another problem, with access control enabled, all webpages with form submit stop to work. For example, if I'll have that feature enabled, when I press "post" on this webpage, it instantly will go to "this page cannot be displayed".

I bought this router solely for one purpose - I was happy with speed of my DIR-300, but I needed gigabit for my computers. So I thought, instead of buying separate switch, I'd better buy a router with gigabit. I was suggested to get TP-LINK 1043, since it's quite popular, alternate firmwares available and so on, but I refused to buy it, since I thought that some chinese company does not worth my attention. So I bought this D-Link (for almost 2x price of TP-Link) and having huge problems as you can see.