I've input cheat into (T) interface like directed, everything seems to work fine like God mode, health, armor, and ghost, but when I ask for (gimmegun cannon or any other weapon) nothing happens. I have the same weapons throughout the whole game. (dual pistols, shotgun, and nail)I am not allowed to pick up anything new. I figure I am inputting the cheat correctly, because in the top right corner, it states (giving cannon). What do I need to do? Or what am I doing wrong here?

you have all the weapons. because normally without cheats, you can only carry 3 weapons. since you have all the weapons by cheats, the only way to get those weapons out is by using "next weapon" key, i use wheelup mouse bottom. 3.2GHZ Intel Pentium EE 840 1GB Dual-channel DDR2-533 RAM Asus P5ND2-SLI Deluxe mobo 2 EVGA E-Geforce 7800GTX Creative Soundblaster X-Fi 550W PSU

hello well this isnt really a question about a cheat, its a question about the game. Its in the end when you half to destroy the 4 blue energy things. I just went down to the last floor and the door wont open, i went back up and that door wont open. What do i do?