Bruce Toski, a computer consultant in Fort Lauderdale, Fla., said that an examination of the certificate causing all the problems shows that it is issued by Thawte Inc., a Cape Town, South Africa-based issuer of SSL certificates that is wholly owned by VeriSign Inc. "One also sees that it is issued to Omniture, which appears to be a company that excels at data mining," said Toski.

He expressed concerns about "encrypted data streams" from PayPal being captured by Omniture, and said until he hears from PayPal about the cause of the issue, he is unwilling to ignore the security warnings he gets when attempting to access PayPal. "Till they tell me otherwise, I have to assume the worst," said Toski, who uses Windows 98.

In an apparent response to such concerns, a poster called Olive from eBay this morning posted a brief statement on the PayPal forum, offering an explanation that differs from the one offered by the spokesman this morning.

"The reason you are receiving the security certificate warning message when visiting the PayPal Web site is due to our recent implementation of Microsoft's Extended Validation certificates," the poster claimed. "We believe that this is occurring mostly for users using older operating systems, like Windows 98. Because Microsoft no longer supports Windows 98, [users of] this software are unable to receive security upgrades and may continue to see this message indefinitely."

The poster also suggested that "specific browser settings or configurations" could cause similar problems for users of more recent operating systems, including Windows XP and Vista. "We are working on diagnosing the situation and hope to have a resolution soon."