inappropriate urinating

Help! I have a 7 month old female kitten. Several months ago, she began urinating in a manner which has become problematic. She begins urinating by squatting, but then stands up, squirting urine outside the box which suggests spraying. She does not "spray" anywhere else but in the litterbox. I thoroughly clean the area but this continued. I consulted my vet and he said that the behavior should cease once she is spayed. Recently I had her spayed but the behavior continues. Now I'm not sure if this behavior will change. Is there a period of adjustment after spaying before the behavior changes? Does anyone have any suggestions?

Just so that I understand...she only does this while standing in the litter box? It starts out with a regualr squatting pee, but while she is peeing she stands up so it squirts outside?

If I got it right, this is exactly what one of mine does. I simply got a larger litter box with very tall sides -- no more problem!

That is exactly what happens! I will look for a bigger box. Thanks.

a cover box might also work (it did for me)

Yes, Loki does that too at times. I call it his elevastor butt. Starts at the ground floor and finishes in the penthouse.

The Problem with a covered litter box it seeped through the slit where top and bottom meet. so, I just got a very deep, plastic, sweater box and no problem.