Yahoo Merchants Solutions (formerly called Yahoo Stores) suffered technical problems that prevented some shoppers from completing purchases on Monday. A message on the Yahoo Merchant Solutions System Status page said characterized the problem as an "Error Message During Checkout" at 8:31 AM (PST). At 5:12 PM (PST), Yahoo posted it was still investigating the issue, apologizing for "the ongoing service interruption for our V3 checkout users (Checkout Manager)."

Yahoo is blaming the problem on heavy holiday traffic. "Cyber Monday" is traditionally a busy day for Internet retailers as consumers head back to work after Thanksgiving weekend in the US.

Yahoo published another update at 6:51 PM (PST) Monday evening, reporting it had made configuration changes. "All merchants are able to accept orders at this time with slower than expected performance. We are continuing to investigate and make additional changes to optimize the checkout experience. Additional updates will be provided as they become available."

http://updates.smallbusiness.yahoo.com