I have a problem getting the "STOCKPILE" Trophy for Resident Evil 5!!!!!!?

I don't know whether it is a glitch on my PS3 but I think I have obtained all available weapons for Resident Evil 5, I even have the "TAKE IT TO THE MAX" Trophy which means I fully upgraded all the weapons. This is why I find it so WEIRD, that I cannot get the Take it to Max trophy. Again I don't know if there is a problem with my PS3 or something else. By the way these are all the weapons I'm sure I have for RES5:

Handguns (HG):

M92F – Given it free near beginning of game. Bought for $2,000.

H&K P8 – Bought for $4,000.

SIG P226 – Bought for $4,000.

M93R – Fully upgrade the M92F and bought for $30,000.

Shotguns (SG):

Ithaca M37 – Found in Chapter 1-2 or bought for $2,000.

M3 – Found in Chapter 3-3 or bought for $4,000.

Jail Breaker – Found in Chapter 6-1 or bought for $4,000.

Hydra – Fully upgrade the Ithaca M37 and bought for $30,000.

Machine Guns (MG):

VZ61 – Found in Chapter 1-1 or bought for $2,000.

AK-74 – Found in Chapter 5-1 or bought for $4,000.

H&K MP5 – Found in Chapter 2-1 or bought for $2,000.

SIG 556 – Found in Chapter 5-2 or bought for $4,000.

Gatling Gun – Fully upgrade the VZ61and bought for $50,000.

Rifles (RIF):

S75 – Found in Chapter 2-1 or bought for $2,000.

Dragunov SVD – Found in Chapter 2-2 or bought for $4,000.

H&K PSG-1 – Found in Chapter 5-3 or bought for $4,000.

Longbow – Fully upgrade the S75 and bought for $50,000.

Magnums (MAG):

S&W M29 – Found in Chapter 3-1 or bought for $4,000.

L. Hawk – Found in Chapter 5-3 or bought for $5,000.

S&W M500 – Fully upgrade the S&W M29 and bought for $30,000.

Other:

Grenade Launcher – Found in Chapter 4-1 or bought for $10,000.

Rocket Launcher – Found in Chapter 3-1 or bought for $10,000.

Stun Rod – Bought for $3,000 (after completion of Chapter 2-3).

Proximity Bomb – Various locations or bought for $1,500.

Hand Grenade – Various locations.

Incendiary Grenade – Various locations.

Flash Grenade – Various locations.

What do I have to do? Any ideas? That's the only trophy I need to get the Platinum Trophy. I'm desperate. Thank you in advance.