Re: Now problems with Ethmoid sinuses..
First of all, I'm sorry that you're still having issues. What your surgeon told you only partly makes sense so I would really encourage you to get a second opinion from an ENT who truly specializes in treating sinus disease (if you'll let me know where you live I'll try to get a recommendation for you).
If the original CT Scan had been done correctly, it should have revealed issues with your ethmoid sinuses (though they are harder to see because they are small pockets that could have been obscured by the inflammation in your other sinuses).
Having said that, the ethmoid sinuses aren't deeper in the skull or particularly difficult to access surgically, they are basically situation between your eyes (the frontal and sphenoid sinuses are the most difficult surgical challenge and require special equipment to safely access during surgery).
It's also just plain wrong for you doctor to say that irrigation won't help with the ethmoid sinuses - a 2002 study on sinus irrigation found that all of the methods of irrigation they tested delivered the saline solution effectively to the ethmoid sinuses.
Before you go see another surgeon and possibly have additional surgery, you really should find a doctor who will aggressively treat your condition medically (with oral and inhaled steroids to shrink inflammation, antibiotics, and possible other medications like Singulair that help stop inflammation from recurring). Surgery is only a temporary fix if you don't treat the underlying cause of the inflammation so it's best to deal with the cause before even considering more surgery.