Mac App Store has become dog slow after 10.6.7 update on latest MacBook Pro Ever since rolling out the 10.6.7 update on my latest MacBook Pro (15", i7), I have found that Mac App Store has become awfully slow. Starting it alone takes anywhere from two to four minutes for the application to become functional and start responding. During that time, the application seems to get lost into the 'not responding state', with the spinning beach ball showing up. 

I looked into the output of Console.app, hoping to find any clues as to what's going on. I found a series of entries to the effect of:

5/6/11 1:55:58 PM   [0x0-0x95c95c].com.apple.appstore[16533]    Fri May  6 13:55:58 mbp App Store[16533] &lt;Error&gt;: CGBitmapContextGetBitsPerComponent: invalid context 0x100610e10
5/6/11 1:55:58 PM   [0x0-0x95c95c].com.apple.appstore[16533]    This isn't a bitmap context. Forcing destination format to ARGB_8 for CGContext.


What is strange is that I have a late-2009 white MacBook model which is booting the same version of OS X: 10.6.7. Mac App Store loads quickly on that machine. However, in the output of Console.app on that machine, I also see similar errors. I am wondering whether these errors have anything to do with the sluggish behaviour of Mac App Store application on my MacBook Pro (clearly, it works fine from the sluggish point of view on my slower, older white MacBook). 

If you require any specific, particular information, I'd be more than happy to provide it. I'm looking for any insights, clues as to what is going on, and what I can possibly do to fix it. 

Many thanks.
Did you by any change change the Certificate settings in Keychain Access?

If so, that's the source of your problem. Go back to Keychain Access > Preferences > Certificates and turn Certificate Revocation List: off.

The Mac App Store should be snappy again after that.