I must know-- how is your conure?? I know that it's been a month or two since your last post, but now I'm really curious about how he/she is!
I have a gcc name Buddy, and I had a similar situation a couple of months ago. I'm not even sure what happened to him; I got him of his sleep cage one morning, and all of us a sudden he was limping and wouldn't stand on one of his feet. Like your bird, mine wasn't whimpering or anything, but I was still so, so worried. I took Buddy to the vet a few days later, and he thankfully ended up being totally fine. The vet thought that he might have twisted his foot at night somehow (weird).
Since the person who responded to your post seems so knowledgeable (I'm sorry that I can't remember your name, but your pic with your bird is really cute!), I just thought that I would ask you a couple things:
I had my conures toenails clipped, and when he came back almost every one of his little toes was bloody (with the coagulant powder on though), which the vet said basically had to be done if I didn't want to have to be bringing him back in every other month. That was a couple of months (at least) ago if not longer, and he STILL can't adequately grip anything with this nails (like my shirt, or any other sort of fabric), which isn't a big deal, but not the best since he's clipped and can easily just fall off my should. The vet seems reputable, so I'm just wondering if this is normal or if she overclipped. She also checked out his wings (which I clip myself and have for years) and said that I've been clipping the wrong feathers all this time-- the outermost long feathers rather than the feathers in the middle area of his wing. I have never heard nor seen this before on a bird, so I guess that's why I'm questioning this vet altogether. I just want to get the best care for my bird!
Thanks so much for any help, and again, I hope that your little conure is doing great!