Samsung Galaxy S3 is facing issues prior to its grand U.S. launch on June 21. Two wireless carriers have been reported to opt out of Dropbox’s 50GB of free cloud space.

According to the customer support page of Dropbox, Verizon and AT&T have decided not to participate in the promotion, which would enable all new Samsung phones with preinstalled Dropbox to have up to 48 additional GB on top of the basic 2GB for a limited time.

“Select carriers have opted-out of the promotion on phones otherwise eligible. Unfortunately, AT&T and Verizon are among these carriers not currently participating,” wrote Dropbox on its customer support website.

Dropbox and the carriers have not specified the reason why.

Tom Cheredar of Venturebeat suspects two reasons for Verizon and AT&T to opt out. First, according to Cheredar, the wireless carriers are worried about the strain on their network, or they may be planning their own cloud service.

But would fans worry over the extra space that will require subscription after two years?

Actually, Samsung has a bigger challenge to face.

Last week, Apple has attempted to ban the Android-based smart phone from entering United States, claiming that Galaxy S3 has infringed at least two of Apple’s patents

“It is no coincidence that Samsung's latest products look a lot like the iPhone and the iPad devices, from the shape of the hardware to the user interface and even the packaging. This kind of blatant copying is wrong and we need to protect the Apple's intellectual property when companies steal our ideas,” said Steve Park, a spokesman for Apple.

Samsung responded back by saying their device is “innovative and distinctive” and said that the “U.S. launch and sales of the Galaxy S3 will proceed as planned”.

The anticipated smart phone will have a 4.8-inch Super AMOLD display, dual-core 1.5 GHz Snapdragon processor, and 2GB or RAM. The design and brand will have no change across all five different carriers.

When Samsung announced the U.S. launch of its Galaxy S3, people expected it to be the iPhone 4S challenger, selling more and faster than Apple’s smart phone. But with all these emerging problems, it is questionable whether the Android-equipped device will have a good start.

If there are no further patent infringement issues, it will be available in the U.S. market on June 21 from Sprint and T-Mobile. Verizon, AT&T, and U.S. Cellular will make them available at a later date.