Please help us help you better and post the problematic script together with its data here.

Also, make sure that your script is as short as possible while still reproducing the error.

Your code as posted has 145 lines and lots of regular expressions. Which of the regular expressions is relevant to reproduce the problem and which can be left out?

Also, in general, consider not using regular expressions (even Perl "regular" expressions) for parsing HTML and instead consider using an HTML parser.