Inaccurate?

Awaken Spell Resistance

( Draconomicon, p. 67)

[Monster]

You gain spell resistance.

Prerequisite

CON 13, dragon type,

Benefit

You gain innate spell resistance equal to your racial Hit Dice.

Special

If your racial Hit Dice increase after you gain this feat, your spell resistance increases as well. If you have this feat and you also have (or later gain) spell resistance as a racial ability, your spell resistance is equal to your new Hit Dice total or your racial spell resistance +2, whichever is higher.

You can take this feat multiple times. Each time you take the feat, your innate spell resistance increases by 2. For example, an old silver dragon that has taken this feat twice has spell resistance 30.