Curious about shadow companions

[The Spectrum Rider]

In the description of the Summon Shadow class ability of the Shadowdancer PrC, the DMG says: "Every third level gained by the shadowdancer adds +2 HD... to her shadow companion. For example, a 9th-level shadowdancer can have a shadow companion with 6 HD."

Can someone parse this out for me? I'd think a 9th-level shadowdancer would add + 6 HD to the shadow's original 3 HD, for a total of 9. But maybe I'm counting from the wrong point. What's the formula?

The Spectrum Rider

 

[AuraSeer]

The shadowdancer cannot summon a companion at all until 3rd level.

At 3rd level, the companion has normal HD. Each three levels after that, it gains +2 HD.

 

[The Spectrum Rider]

So at 9th level it should have 7 HD?

(There's no way to get from 3 to 6 by adding 2's, which is why I was so confused in the first place.)

Also, what about the shadow companions the shadowdancer summons later in her career? Do they start at 3 and go up 2 for every 3 (new) levels of the shadowdancer, or do they start equal to their earlier-summoned companion?

The Spectrum Rider

 

[AuraSeer]

So at 9th level it should have 7 HD?

(There's no way to get from 3 to 6 by adding 2's, which is why I was so confused in the first place.)

7HD, yes.

Also, what about the shadow companions the shadowdancer summons later in her career?

There aren't any. The character has only one shadow companion at a time, ever. He cannot summon another unless the first is dismissed or killed.

On the class advancement chart, the lines for 6th and 9th level refer to "summon shadow" only because they increase the power of that ability. (That's the +2 HD.) At no point does the shadowdancer gain extra companions.

 

[Tabarnak Smokeblower]

There aren't any. The character has only one shadow companion at a time, ever. He cannot summon another unless the first is dismissed or killed.

SRD 3.0

Every third level gained by the shadowdancer allows her to summon an additional shadow and adds +2 HD (and the requisite base attack and base save bonus increases) to all her shadow companions.

Was this errata'ed? There is no mention of additional shadow companions in 3.5, though.

Also, just to be absolutely clear, Spectrum Rider's DMG quote was erroneous?

TS