Terrain - Brush selection doesn't work, in all menu's

I got a problem with the terrain.
The title says it all, no matter what brush i select it wont change the actual brush within the editor. Changing the parameters of the selected brush does not change anything either. This goes for changing the actual terrain, painting grass and even textures. Only the first brush keeps being selected with default settings, and it will not change.

I have looked trough the Unity answers and forums and found 2 answers, both came down to this: Re-install Unity.
I don't buy this, because i had this problem before and for some magical reason the problem disappeared 2 days later. I did nothing with the terrain it self, or any assets being used on any terrains even. So i figure it has to be a temp file or something somewhere that is causing this?

If anyone can offer me a solution to this problem i would be grateful

Thanks in advance,
Frans.

 

*Still having the problem, no solution yet. So i am going to bump it back to the first page, anyone got any suggestions?

 

2 weeks later, and i am back. I am not going to post a new threat, just going to bump this one again. I am again running into the same problem. Re installed Unity three times now on two different systems. Within different projects i keep running into this problem after a while on both systems. So i am finding it hard to believe i am the only one having this problem.

Again, i still see some other people with the same problem on Unity Answers, but the "just re install Unity " answer is something i am completely done with. I want to work, i require the terrain tools constantly for my current job and i can expect something like this to work bug free.

What is causing this? And, what is the best way for me to solve this, or maintain a workflow as smooth as possible with this "bug"?

Any help would be greatly appreciated.