The iPhone's 3G incarnation generated lots of hype at its launch, but it's quickly gaining a reputation for having slow data speeds and inconsistent voice service. Indeed, the iPhone 3G has been such a disappointment to a couple of users that they've even sued (one sued the company for allegedly producing misleading advertisements that promised data speeds at twice the rate of the original iPhone). 

Here, we examine the six most common gripes that users have had about the iPhone 3G, from dropped calls to problems with mobile iTunes to lack of enterprise features. (If you'd rather view this story as a slide show, click here.)

Slow data speeds

Admittedly it's silly to sue Apple over slow iPhone 3G data speeds, but this has been one of the most common complaints about the device since its release earlier this summer. 

A recent survey  conducted by Wired Magazine has found that the speed of the iPhone 3G varies significantly from carrier to carrier, and that devices' slow data speeds in some areas may have much more to do with the quality of the 3G network they're running on than with the devices themselves. 

T-Mobile, which offers the iPhone 3G in Germany, offered the fastest average data speeds at 1,822Kbps, while iPhone 3G users in Australia experienced the slowest speeds at 759Kbps.

Dropped calls

For a company that prides itself first and foremost as a voice carrier, AT&T can't be happy to hear reports of dropped calls on the iPhone 3G. 

Network World's own Jason Meserve has said that he initially experienced voice call problems with his iPhone, because the device frequently would drop his call after a couple of rings, even in zones where the device said it had solid coverage. He remedied this problem, however, by downloading the 2.02 firmware update designed to eliminate the call-dropping problems.

Weak indoor signal quality

Even if users' calls aren't being dropped, many are still complaining about weak indoor signal power, which they say is negatively affecting their overall call quality. While no one from Apple or AT&T officially has placed the blame for poor signal strength on anyone, there have been grumblings that a faulty chipset supplied by mobile chip maker Infineon Technologies may be the primary culprit. 

Independently, Wall Street analyst Richard Windsor of Nomura Securities also tagged the Infineon chipset as a potential cause of poor signal quality and said the device's problems were related primarily to "an immature chipset and radio protocol stack."