Sporadic 'problems' block access to Amazon.com
Outages have lasted much of day in more than 2 dozen cities
(CNN) -- Some Internet shoppers who tried to visit Amazon.com on Monday were unable to access the popular book, electronic and toy sales Web site due to an undisclosed problem, which produced the error message "http//1.1 service unavailable" on-and-off during the day.
"It's just the fact that we have a very complicated system that has problems from time to time," spokesman Craig Berman said.
He would not say if the problem was due to volume, an internal error or an intrusion of some sort.
Keynote, a San Mateo, California-based company that monitors Internet performance, told CNN the problems were widespread.
"In over 25 metropolitan locations most of the requests for pages on Amazon were not able to be served completely, or correctly," said Roopak Patel, a senior Internet analyst at Keynote.
Patel said the biggest problems occurred between 11 a.m. and 12:40 p.m. ET, and again between 2 p.m. and 3 p.m. ET. He said the problems persisted through 6 p.m. ET in more than 75 percent of the locations being monitored.
"At this point we can't rule anything out," Patel said.
He said the problems were first noticed about 10 a.m. ET.