I tried parse out special characters from thread title so that file name will be nice but some may be missed. In your example it was : char. It's no big deal but if it bothers you, there are 2 possible solutions:
1- edit line:
$filename=preg_replace("/[.!\\\?\^\'\"\$]/", '', $thread[title]);
and replace it as:
$filename=preg_replace("/[.!:\\\?\^\'\"\$]/", '', $thread[title]);
(This will parse out : char too)
2- If you are not interested in naming the file name after thread title, replace the same line as:
PHP Code:
$filename='Thread'.$threadid;
After the change all file names will be like "Thread1244.txt" and no more file name bugs. However I personally prefer to use thread title as file name, it is much better IMO..
Your call