MAngband

This isn't exactly a bug, depending on how you look at it.

Here in MAngband, monsters summon creatures all around the player.
In Angband 3.0.9b, monsters summon stuff around themselves.

There's a HUGE difference by being surrounded by monsters or having monsters summoned away from yourself.

ZAL

Indeed :)
The purpose of the latest Angband releases was to make mage almost impossible to play. So you got:
- GoI removed
- summons near the caster (makes your runes ineffective since summoned stuff now can summon even more and breathe or cast stuff on you)
- nerfed Rift spell (monsters have monsterlvl/127 chance of avoiding the teleporting effect)
- and probably more I don't remember