I might be wrong but I don't think that's the case. I once wrote a bot that scraped a page and submitted a dynamic form 10 times per search query for sometimes hundreds of searches/page scrapes from a slow server.. and it often gave up after a few minutes. I also created a link popularity script to parse engines and that occassionally timed out as well.

In reality I need to find a way to break up the uploaded zip archive and upload for X minutes (or X MB, or X files), load a page and meta refresh, and then start where I left off.