When you say "hang", do you mean you have to kill the process, or the client browser hangs? Is it possible that some of that data that you're including directly from the database is being misinterpreted as the start of a string, or other HTML element? In any case you should probably be escaping them with something like HTML::Escape.

What happens if you replace fetchrow() in the while loop with something that just supplies test data from an array?