I noticed that in flans mod, when in the zombie gamemode, once a player is infected, he is respawned as himself, same kit without even the option to choose a zombie kit. If he is killed again, same applies.
However, pressing G will show the zombie and survivor option and clicking zombie will allow the choosing of a kit. On respawn player will respawn as that kit.
Server is running cauldron however, that may be the issue I am looking into it.
Flansmod version is 4.10.0
Content packs are the official ones, and one i made to add another zombie team with guns, with short name hellbents and longname Hell's Minions

Confirmed. The Zombies spawn normally when using straight up forge instead of kCauldron. Is there a way I can get flans worknig with kCauldron in 1.7?