By auto-refresh, I assume you're referring to the fact that when you switch from one Safari page to another and then return it often refreshes the page rather than simply using the cached version?
This is caused by a lack of system memory (RAM). If you switch the iPad off completely and then on again prior to using Safari, this frees up unused RAM and reduces but does not eliminate the problem. There is no other way - Safari does not cache web pages in main (flash) memory, so the space available - 256MB in the iPad1 and 512MB in the iPad2 - is limited and, depending upon the complexity of the currently viewed page, Safari may be forced to remove cached pages from RAM to make space for the current displayed page.
Tim