Xbox 360 users have kicked off an informal Internet poll in which 16 per cent of respondents said they are having problems with their new gaming console, although Microsoft says there are no major bugs and that problems have been reported with only a very small proportion its machines.

The forum on Teamxbox.com had gathered 496 responses as of Friday morning UK time, with 80 users saying they had found problems with their new Xbox 360 consoles, which went on sale in the US this week. The poll is at http://forum.teamxbox.com/showthread.php?t=392599

Users experiencing problems are more likely to respond to such a poll than those who are not, meaning the proportion of machines affected is likely to be lower than the poll suggests. Users who are happy with their consoles are likely too busy playing games to fill out a survey, we reckon.

Still, problems reported on Web discussion boards included the Xbox 360 shutting down unexpectedly during play. At least one user posted a screen shot reporting a system error. Others thought their systems may be overheating.

One user said his Xbox switched off after 30 to 40 minutes playing Perfect Dark Zero. He took a break, restarted the machine and played for 30 minutes before it shut down again. An indicator light on his Xbox had changed to orange, he said.

"I looked in the manual and it looks like it's an overheating problem," he wrote on Teambox.com. "We tried opening a window and putting it beside it. This made little to no difference. Anyways, I woke up in the middle of the night to try it again and it just shut off. Man this sucks."

Others reported having no problems at all: "Bottom line: the jaggies aren't there. It looks beautiful. ... Controller is awesome. 360 interface rocks."

Another user said his machine ran for six to seven hours "flawlessly."

Microsoft characterized the problems as minor and said there are "no systemic issues" with the Xbox 360.

"We have had a few isolated reports (of problems)," said Claire Dabreo, a spokeswoman with a Microsoft public relations company in the UK.

"Like any major consumer electronics launch it's very complicated and there's always, unfortunately, going to be some percentage that's not going to work perfectly," she said. "But it's an incredibly small fraction and below what you would expect for a launch of this size."

A representative from Wistron, a Taiwanese contract manufacturer that's making Xbox 360s for Microsoft, said he did not know how many machines would typically be defective in a launch on the scale of the Xbox 360's. "I can't comment on this," said Wistron representative John Collins.

The reports of sporadic defects appear not to have dampened enthusiasm for the consoles. On eBay's auction site the game machines are still attracting bids twice as high as the $399.99 retail price for the top-end Xbox 360 Premium edition machine.