USB port on Apple Display won't charge my iPhone 4

[BigGarb]

I always used to use the USB port on the back of my Apple Display to charge my iPhone 3G with no problems. I connected my iPhone 4 to the same port and it will not charge. I have to hook it up directly to the port on my MacPro instead.

What gives?

 

[animatedude]

the 24'' or the 30''?

edit: does the 30'' have a USB ports? i dunno..

 

[BigGarb]

the 24'' or the 30''?

edit: does the 30'' have a USB ports? i dunno..

actually it's the 23" HD

 

[cherry su]

the 24'' or the 30''?

edit: does the 30'' have a USB ports? i dunno..

Yes, the 30" has 2 USB ports and 2 FireWire 400 ports.

 

[TexasBlake]

My 30" will charge it. Just plugged it in to check.