I haven't checked this for Survival, only Creative. And as far as it showed, it didn't happen for the Right mouse button. Only the left. I don't believe it's my computer having a problem with Minecraft, because it's only been happening since the latest update. (1.5)

I expected the block destroying to happen normally when holding down the left mouse button.

The mouse cursor began to show immediately after pressing the left mouse button, and stopped controlling the camera rotation, and then paused the game 2-3 seconds afterwards.

Steps to Reproduce:
1. Hold left mouse button
2. Hold for 2-3 seconds
3. Watch menu open