Simple RAW for 3.5: 38 pages, and I still don't know how to play D&D

[Shinoskay]

Rules Compendium, page 79.



Ultimate magus contains the following clause:

At each level except 1st, 4th, and 7th, you gain new spells per day and an increase in caster level (and spells known, if applicable) as if you had also gained a level in both a prepared arcane casting class and a spontaneous arcane casting class to which you belonged before adding the prestige class level. You do not, however, gain any other benefit a character of those classes would have gained.

...which explicitly limits its advancement to spells per day, caster level, spells known, and that's it. It does not increase your effective level for any other purpose.

And that matches standard prestige class language, I concede.