(((((Alice))))) hang in there!!! you really are seeing some good results intermittently, so I think if you keep refining your doses you can get there. The highs could because this 3.8 had a 3.0 behind it (previous dose), so the possible loss of overlap going into the shot could have reduced its effectiveness. Maybe just write today off as "day of c*rap"

, regroup (go see a movie tonight, or at least indulge in some chocolate!!!), and try again tomorrow.
Since you are getting a clear response on ProZ I'd stick it out, but if you do decide to switch I don't think there's anything wrong with that either. When I was struggling, sometimes I'd set a deadline for myself "I'll give it one more month & if I can't get consistent good #s I am switching" or such, and that helped me feel more in control of things.
I don't know if overlap works the same with Tabby as with Bix, but with BIx, I often got significantly better results on the 3rd shot at a dose, like the 1st 2 were just a build-up. If you look at Tabby's #s from that perspective, when you moved to 3.8u, it was after the 3rd shot on that that you got the great PS, so that could be overlap in play. So then moving to the 3.0 gave you great #s on that one cycle, but you could have been losing overlap by the end of it, so last night's 3.8 wasn't as effective. If you try 3.8u again for a few cycles and see a good PS again after the 3rd or 4th shot, I'd guess that might be why. If that is the case, you may find you can't reduce as much on the lower PS - maybe just to 3.6 or 3.4 or something. Either that or if you reduced back to something like 3u, then you'd expect on the following shot you would have to shoot more than usual. This is one reason I never succeeded with a sliding scale

every shot is affected by the shot or two that came before it, so you can't just take the PS (or at least I found I couldn't) out of context and decide the dose on just that. Of course ECID so that may not be the case at all for Tabby, but just sharing what I saw with Bix in case it is of help....
Often too, I found that just when I felt like giving up was right before things really improved, like when you are climbing a big hill & think this will NEVER end, & then all of a sudden it turns out you are at the top! Hoping that this is one of those cases for you.
