As Jacob mentioned, the settings controlling various 'flood' attacks, are still present, there's simply no GUI. To see and edit the settings, you can either edit any or the configuration (.cfgx) files, found in:
C:\Program Files\COMODO\COMODO Internet Security
COMODO - Firewall Security.cfgx
COMODO - Internet Security.cfgx
COMODO - Proactive Security.cfgx
See image 1
Or edit the registry:
See image 2
Although it's possible to change these settings, unless you understand the consequences of any changes you make, you could damage your installation or otherwise prevent the firewall from behaving optimally.
If you're using Windows 7, the tcp/ip stack has been 'hardened' in a way that counters various 'flood' attacks. if you're using Windows XP, you can find additions information about hardening here
. For additional protection, make sure you're behind a router that implements 'flood' protection.