I noticed that at the end of october, when I got my Promo of Ashes, but I thought, OK - an error in promo CD but I wondered much when I bought the album - the misspelling was there too. Of course, it doesn't matter but I thought a lot about the intention and meaning - maybe it's a reffering to ISIS (egyptian goddes)
It could indeed be a reference to ISIS.
Take a look at this page : http://www.touregypt.net/isis.htm
Especially this excerpt :
"Thus when she wished to make Ra reveal to her his greatest and most secret name, she made a venomous reptile out of dust mixed with the spittle of the god, and by uttering over it certain words of power she made it to bite Ra as he passed. When she had succeeded in obtaining from the god his most hidden name, which he only revealed because he was on the point of death, she uttered words which had the effect of driving the poison out of his limbs, and Ra recovered."
And compare to some words of the song :
"There is only one way out
One word left to shout
I will find the truth within your skin
You try to sink me in the mud "