Problems with last few beers

I have had problems with 2 of my last 3 beers. Both the beers that turned out poorly have had a sort of soapy/astringent off taste to them. Also all 3 of them have been poorly carbonated. I have never had either of these problems with any of the other beers I've made. The only thing that is new/different for those 3 is that I started using IO Star no rinse sanitizer. I am wondering if I am mixing it to heavy or something. Which seems hard since the bottle has a built in 1 oz our spout but that all I can think of. I am planning on brewing up round 2 of my PB Oatmeal Stout tomorrow and I really dont want this problem to happen again, so any suggestions about what you think the problem might be would be great.

Check here to see if your problem is listed:

http://www.winning-homebrew.com/off-flavors.html

The only thing I got from that that I could have done wrong was maybe overhop. I did an APA and IPA on the two beers that turned out poorly and I put extra hops in both of them. The third was a Saison so it was lightly hopped.