Well, since it's a case of everything is going fine one minute and then a little while later it's sluggish and then a little later everything is fine again, I don't think that is it. And yes, I clean everything regularly. Have you never seen it where it takes notions and you can just clear all the caches and then open a page and it's filled again immediately? Some days it does that to me.
Right now it is working fine. This morning, slow as molasses.