timming error - Joomla! Forum - community, help and support

i have joomla installed on website. when click on manage categories tab or manage products tab page times out , message reads "website cannot display page, causes - website under maintance - website has programming errors" why happening????

mod note: crosspost deleted. please not crosspost messages. see forum rules: http://forum.joomla.org/index.php/topic,65.0.html

welcome joomla!

that error not seem error generated joomla...

could give more info locate problem:
what os (linux / windows )?
what webserver (apache / win iis)
what php version?
what mysql version?
what joomla version?
what kind of hosting (shared?) , provider?
url of site?