A few times in places discussing the Magus I have seen people claim that when casting a touch spell you can cast the spell, use your move action to move adjacent to a target, then make the touch attack, to avoid having to cast defensively.
I can't find where in the rules it says this.
The closest I can see is having your familiar deliver the spell (Since it has its own actions, it can move away from you and then make its own touch attack) or, as a magus, beginning spell combat while 10' away, casting the spell into your weapon with spellstrike, and then 5' stepping up to your target and making your weapon attacks. Of course you can also cast one round, hold the charge, and then move into position and attack on subsequent rounds, but this sounds more like a strategy to use when you desperately cannot afford to fail that concentration check rather than something to use regularly.
Is this people getting mixed up, a common houserule, or what?
In the "Casting Spells" section, touch spells, it says you deliver the spell in the same round you cast it, not in the same action.
Since the only restriction is "same round", you can cast, move and deliver.
Any other action you can normally take is valid too, so you could for example cast, use a swift action, move, call someone names and then deliver the spell.