Yep, the very same, I've double checked with other threads... (e.g http://www.pokemonreborn.com/forum/?showtopic=5933) ... and gone to the same place under the same conditions, no luck. I've left the area and done some basic debugging to no success
EDIT: Not sure what I did, but after several restarts and leaving the area etc Joltik appeared. Probably wasn't the right time of night...