Yeah, it is. As for me, it concers file uploads. In case it was file attached to bug on first report, it will end up with #200 error.

It turns out to be caused by copying special characters (like special quotation marks) from Word into IE for posting on Mantis. Someone on the Help list posted a workaround. I'm posting this blindly--I didn't really read it and don't know if it works or why it does, if it does:

Hey i've found out that when i check the "Report Stay" checkbox then i
can report a bug with the special quotes and it work with the IE !!!

Ok, here is a simple hack!! for the special quotes problem:

insert this line:

<input type="hidden" name="dummy__6666">

into the bug_report_page.php under the line 239 :

<input tabindex="11" type="checkbox" name="report_stay" <?php check_checked( $f_report_stay ) ?> /> (<?php echo lang_get( 'check_report_more_bugs' ) ?>)

so there is a dummy var in the $_POST of php and then all other var are ok....

I don't know why... but now i can add Bug with copy and Paste from MS Word to Mantis via IE ...

Is a quoting problem. Reported by me today.