My App store wont load and beachballs.

I realy don't know why this is happening. I click my app store and it stalls, it wont load and it beachballs constantly. I wait but nothing happenes, so i have to force close it. Its weird becase i can update my software through "software update..." which takes me to the App Store anyway, and that loads instantly. I have no clue what is going on and the only thing it may be is that i installed a new SSD the other day and i had to install Mountain Lion on it, I even bought Mountain Lion for the intention of doing this. Is there any solution to this? Is it a common occurance? I need help on this because i need to reinstall important softwares that i had before. My Mac is a Macboon Pro 13" late 2011. Any help would be apreciated, cheers.