Hi,

Sadly the TC client is not compatible with Modloader, which is necessary for a very big part of Client mods. Is there a way to fix this?

The terrain generation is not needed most of the time - so what about a "light" version of TC that is only for playing?
I mean without terrain generation the code needed to get the information for custom biomes from already generated worlds (singleplayer and bukkit) into BiomeGenBase.class, so colours and temperature works.

Hmm incompatible in what class ?

alb.class
and
vx.class

(I think)

Hmm you may override Modloader alb.class by TC and try ..
Otherwise this need special version for modloader :(