Two-thirds of iPhone owners are holding off upgrading to the iPhone 4 because of the device's antenna problems.
In a survey conducted on Friday, 66 percent of current iPhone owners told IDC that they were waiting longer than they otherwise would have to upgrade.
The normal iPhone upgrade cycle has been noticeably delayed - and some people who had intended to buy an iPhone 4 may now never do so.
IDC says that whether or not potential customers go ahead with a purchase will depend on the effectiveness of its efforts to mollify customers - and it remains to be seen whether a bumper or refund will really hit the spot.
"We are pleased that Apple is working with its customers to offset the reception issues related to the iPhone 4," says William Stofega, program director for mobile device technology and trends at IDC.
"It will be interesting to monitor the effect of Apple's response to the antenna problem over the next several months."
Interestingly, non-iPhone users don't seem to be nearly so bothered about the issue. Three-quarters of those who said they'd been planning to buy the iPhone 4 said they didn't intend to delay their purchase.
This may conceivably be related to Steve Jobs' controversial claim on Friday morning that other smartphones suffer from the same 'death grip' problem as the iPhone. Could it possibly be the case that non-iPhone users believe him, while his existing customers don't?