Market Place and certain apps not loading

[ec4585]

I'm trying to access the Marketplace and everytime I tap to load it, a white screen comes up for a couple of seconds and then disappears again, showing the desktop (or apps menu) and there's no indication of anything having loaded or working. This also does this with a few of my other apps, but not all of them.

I can do this repeatedly without having to reset my HTC; same thing happens each time. There is no error message. I have restarted my phone and am trying to figure out a way to fix this without resetting it completely.

Anyone have any ideas or tips?