Per the Wiki:
Tested on 3 Wizard (Shadow Mage)/10 Shadowdancer with 20 base INT. Could only cast level 0, 1, & 2 spells. Shadowdancer levels were not applying to CL for the purposes of attaining Spell Levels. Nor for the purposes of spell slots. It was only counting for durations.Arelith Wiki wrote:Shadow Mages don't gain sneak dice from their Shadow. Instead, they gain 1 caster level for every Shadowdancer class level.