Right click on the gun, make sure it's Main FPI file is weapon.FPI, not weaponglow.FPI. weaponglow.FPI causes the gun to float up and down annoyingly.
Cheers
PwP
EDIT: Oh, sorry, just looked at the first pic closely, not sure what the problem is...
Try this:
;Artificial Intelligence Script
;Header
desc = Weapon Pickup
;Triggers
:state=0:hudreset,hudx=50,hudy=90,hudimagefine=gamecore\text\pickedupaweapon.tga,hudname=weaponprompt,hudhide=1,hudmake=display,state=10
:state=10,plrdistwithin=40:state=1,playertake,coloff,rundecal=-1,plrsound=audiobank\items\pickupweapon.wav,hudshow=weaponprompt,hudfadeout=weaponprompt
;state=2:state=3,playerdrop,colon,plrsound=audiobank\items\pickup.wav
:state=3,plrdistfurther=65:state=10
;End of Script
Put that into an blank FPI file (you can use Notepad to edit and save FPI files) and set it as the new weapon's main script.