Game Mechanics: line of sight issues

[Crenshinabon]

It was odd because I remember some things causing los issues and some thigs did not. I remember my enchanter in classic in highkeep could stand a floor above someone and cast on them, but I also remember people losing me on hills and shit. Can't really remember the timeframes.

[Arillious]

I'm seeing similar issues with LoS where I cannot complete a cast because a player or NPC goes over a small hill(I can still see them).