frustrated_alot,
Looks like my type of case. My name check was cleared since March & the USCIS was still doing their additional checks. I got my 2nd FP done on September 4th and then my IL was issued exactly a week later. What does that tell you? I am hoping that you will hear some good news, I mean your interview letter by end of this month. If you don't get anything in the mail, please do call that cust service number and have them take a look at your file by your A # to see where you exactly are in the process.
Again, good luck and I am praying for you & hoping that you will be posting a good news pretty soon. You have been extremely patient and I am sure you will be rewarded.
Take care & all the best.