I finished the toad village quest before I gave Mekdawa the potion. Now, even if I have given Mekdawa the potion and he has thanked me for it, I'm not getting any credit at the priest guild. Any ideas???

Go back to Mekdawa and buy the potion back from him...Give him the potion again and go back to guild. This should work. Good luck..

I also finished the toad village before I found out about Mekdawa and the potion, the difficulty I had was getting him to take the potion, he just kept running around asking why I hadn't gone to help the toad village (ridiculous when I had finished that quest!) and wouldn't talk to me...I stood there with the potion ready on "give" and clicked on him as soon as he came back...he thanked me, and when I got back to the village I had no problems I got the experience OK.

I finally got it to work. I think maybe I had been holding down the Ctrl button when I was trying to give the potion (duh). worked when I just selected use/give and left-clicked. thanks for the assistance.