True drakes have a few additional powers they can get like magical guard and dragonspeech. Are these also active only in their drake form or are these active also in their metahuman form?
Since true drakes are dracoforms that assume a metahuman form, I would assume that they use the Shift (Human) ability associated with shapeshifters found in the Runner's Companion. (In contrast drake's are metahumans that assume a dracoform using Shift (Drake))
A shapeshifter can only assume a single, specific human form, chosen at character creation. This form is the same gender as the animal, and generally shares other traits as well—eyes of the same color, hair similar to the animal’s fur or plumage, distinctive scars and injuries, tattoos, etc. The human form’s apparent ethnicity is often (but not always), similar to that of humans residing in its native area and possesses unique fingerprints and retinas which are consistent from transformation to transformation. Samples of tissue taken from the human form will show animal, not human, DNA and can serve as material links (see Material Links, p. 28, Street Magic) to the character regardless of current form. Shapeshifters retain all of their powers and weaknesses in shifted human form except for their Natural Weapon. (Source: Runner's Companion pg.88, emphasis mine)
Since I can't find any specific ruling within the text for true drake characters (The Clutch of Dragons, pg.137) then I would assume the general ruling found here applies. (And, in any case, why would a run-of-the mill shapeshifter be the more powerful of the two and retain all of it's powers in metahuman form while the true drake does not?)