Owners of the new iPhone 5 are reporting a sticky problem with the new "Lightning" cable used to connect their handsets to power sources or computers sticking in USB sockets.

Lightning is Apple's replacement for its 30-pin connector and terminates in a standard type A USB plug, as featured in USB memory sticks and pictured at left.

Owners of the new cable have found, according to posts in Apple's Support Communities, that the connector fits rather too tightly into USB ports on a variety of devices. In some cases it has proved impossible to remove.

One Apple customer, posting under the name 'gvilledh', explained his experience as follows:

"I went to unplug the USB cable from the wall wart and it was extremely tight. The white sleeve over the connection started to slide off, but I was able to get it out."

gvilledh took his cable back to an Apple store where it was replaced, but he says " My new one is still tight, but not as bad as the first one."

Another poster, iGixer, had a similar issue:

So I tried to unplug my brand new Lightning connector from the white power block and the white plastic surrounding the USB end slides right of revealing the medal connectors

The source of the problem seems to be the two small rectangles cut into one side of the USB A plug, with posters reporting they are a little deeper than those in other connectors. That extra depth seems to result in the tines of a USB socket digging in to a depth at which they won't easily slide out.

Some posters say downward pressure, to angle the USB plug down a little, helps to withdraw it from the socket.

Apple had not responded to a request for comment at the time of publication. ®