Some of my weapons disappear when I equip or unequip them. Does anyone have this problem?

This may be a stupid question but are you sure you are not dropping the to the ground instead of unequipping?

Another stupid question. When you unequip something it goes to the very bottom of your inventory, are you sure the items are dissapearing and not just reordering or stacking?

Thanks for the replies. I'm going to stick to using the holster/upholster button. That should fix my problems.

What is the holster/unholster button by the way?

I recollect the b button also works for this, yes?

Huh?
what weapons/items you have equipped has little bearing on what your character can do with their hands outside of combat. If you need to pick a lock, for example, you can equip some lockpicks in one slot and then clicking on it will change the cursor to the Use cursor and you can click on a door to attempt to pick the lock. Otherwise you leave your 2 slots alone and right click on the locked door to access your inventory and use your lockpicks. Either way it is entirely dependant on your skill as to how easy it is to pick the lock, the equipment slots are irrelevant.

Every single time you want to climb a ladder, your character twirls his gun like a trickshooter and holsters it. Every single time you want to fiddle with a computer, your character puts away or draws his hammer.
Yes, many experienced players prefer that at least one 'hand' have something innocuous which doesn't spawn an animation. It's half the joy of the Unarmed skill, really.

I prefer flowers, personally, or an iguana-on-a-stick. Something innocuous, you know, to catch people off their guard before you whip out a Turbo Plasma Rifle or a Rocket Launcher.

Oh! Okay, now I see.

Yes, not having a weapon out makes scenery interactions quicker. I won't argue that point.