HOW DO I STOP COMODO FROM NOT ALLOWING ME TO ACCESS LIMEWIRE?
EITHER APPROVE LIMEWIRE AS AN APP OR SET UP A NETWORK MONITOR RULE.
And then stop shouting, please.
Ewen 
First add an application rule as Panic says. ;D (security/tasks/define a new trusted application)
Then open Limewire and set a manual port. Let’s say 44555.
Close Limewire.
Open Comodo Firewall.
Got to Security tab and click on Network monitor,
and right click on the top rule. Choose add/add before and make the same settings as i have.
Action : Allow
Protocol : TCP or UDP
Direction : In
Source IP : Any
Destination IP : Any
Source Port : Any
Destination Port : A single port : 44555
Now restart the firewall (or reboot the PC if it doesn’t work.)
Now you can try if it works.