oka guys i know you guys having been having this issue an seeing alot of people over the net have the same, issue, as this error varies on fix from server to server. i believe you can fix this easily by trying to install sample data using an different browser, i realized that yslow causes this error in firefox, when i treid safari and installed sample data. worked like a charm. Note: on my server i have install serveral joomla sites before. and just this one new domain cause this issue, no need to change anything to file permissions of folders. or configuration-dist file. just try a different browser cause it could be an extension in your firefox browser causes this...