The multicast rate and wide channels setting seem to be okay in your situation. I'd look into other devices possibly causing interference in or around your Time Capsule. Also, if you can, try testing your network with another wireless N machine and see if you have the same disconnection issues (it just may be your MBP that is having issues). If all else fails, it might be that you have to run it in 2.4GHz mode. I know it's not as fast as 5GHz but it should give you greater range and less issues.
numbersyx, if I'm not mistaken mauricio13 is connecting his Time Capsule to a modem/router. Some ISPs only provide a combo modem/router and do not offer a modem by itself. I understand that you disabled the wireless option, but it might be that your modem/router is still doing its own DHCP and that could be conflicting with the Time Capsule. Try disabling DHCP on your modem/router, and if that's not possible then set up your TC to run in Bridge Mode. Go into AirPort Utility > Manual Setup > Internet > Internet Connection and in Connection Sharing dropdown select Off (Bridge Mode). This lets your modem/router do the DHCP/NAT for your network and the TC only acts as a wireless access point. You can also enable your wireless network on your modem/router, allowing b/g clients to join the same network as wireless N clients without slowdown.