iPhone customers are struggling to install Apple’s latest software patch and have been grumbling about the problems on Cupertino’s support forums.

The company released its iOS 4.0.1 update yesterday, and immediately some users began complaining that they couldn’t successfully install it on their iPhones.

“On a Win7 PC. Plugged the iPhone 4 in this morning and told there's an update. Ran it, and it errored during the install - I now have a brick. Now had to do a full restore, and I guess I'll have to try again,” wrote a UK punter with the handle DiscoRobbo on Apple’s forum this morning.

“So far I've had to restore to factory settings (successfully and now on 4.0.1), but now the phone is having to resync ALL my data - which will take a while,” DiscoRobbo added later.

Many customers have been reporting firmware problems with the update, which keeps spewing out ‘error 9’ messages.

iPhone customer PaulDev said that an Apple rep gave him the following explanation for what had gone wrong.

“Error 9: This error occurs when the device unexpectedly drops off of the USB bus and communication stops. This can occur if the device is manually disconnected during the restore process. This issue can be resolved by performing USB isolation troubleshooting, using a different USB dock connector cable, trying another USB port, restoring on another computer, or by eliminating conflicts from third-party security software.”

PaulDev took a sarcastic swipe at Apple.

“Maybe you touched the USB cable in the lower left corner. ‘Don't hold it that way’, okay? Apparently flaky mobile signals weren't enough, with 4.01, they've upgraded wired connections to have the same brilliant reliability was wireless,” he said.

Having read the forum gripes some decided to altogether steer clear of Apple’s update.

“After reading 8 pages of #applefail I think I will hold off updating for now and wait for today's press conference. Pls note however my apple bumper does not solve the reception drop issue,” said georgeyoung on Apple’s forum.

Apple has remained characteristically quiet about this latest in a series of complaints from unhappy fanbois disappointed with their iPhone 4 devices.

The company will be holding a press conference later today about the iPhone 4. It's been reported that Apple won't be recalling the slinky beast, despite the antenna problems that may have prompted the quick iOS 4.0.1 update release yesterday. ®