There was a timing issue with some models so i adjusted the irp files to fix it. If you look you'll see Suffix=1,-78. I replaced th3 78 with 44. Yours will probably work for the VSX-52.
It was the lower end Pioneer models and possibly the VSX-40 that had issues with the wider timing gap. I didn't want to use two different sets of files so I use the 44 for all models. It works for all the models so everyone is happy - I hope.