I'm sure this point has been brought up before by many others, but the problem hasn't been fixed. Capturing points is extremely annoying because you're clicking the tower like mad but it gives off that unavailable sound and you just stand there taking damage like an idiot. This problem has existed since dominion was introduced and would be beneficial if fixed. (It usually happens if you're doing something else like casting a spell or walking around then clicking the tower again - if this is done on purpose to stop people from being too fast it's meaningless and annoying).

Are you talking about how if you stop capping, you can't cap again for a few seconds? If so, it's as intended.

I stopped reading here because I didn't need to read further.
This system is working as intended. If you couldn't notice the circle that counts down OR the debuff on your champion the entire time, you might be an idiot.

Also, let's talk about a REAL bug that can affect the out come of every game.
Let's first identify the process of "capturing"

1) You move up to the tower
2) You right click the tower
3) A short "cast" delay
4) You begin capturing a tower by raising "life" for neutralized towers or destroying "life" for enemy towers.
5) After being interrupted or finish capturing, your channel stops.

The bug happens at the third stage. If your ally is ALREADY capturing a point and you move close enough to capture, you don't have to wait this delay period to increase/decrease capture health. That's right. As long as one player is actively channeling a capture point, nobody else on the team has to wait this delay.

How to replicate/test this:
1) Have someone (ally) start capturing a tower, enemy or neutralized.
2) Time it so right when you start start your channel animation, your ally is either interrupted or manually stops capturing himself.

If done right, you'll notice the "delay" period is skipped for the new champion channeling and the health of the tower will increase/decrease as if he was already channeling (depending on neutralized/enemy).