gmmktime() and negative values on Windows

Support Request Template
What version of phpBB are you using? phpBB 3.0.6
What is your board's URL? http://www.visvangsa.co.za/phpbb35/index.php
Who do you host your board with? winhost
How did you install your board? I used the download package from phpBB.com
Is your board a fresh install or a conversion? Update from a previous version of phpBB3
Do you have any MODs installed? Yes
Is registration required to reproduce this issue? Yes
What version of phpBB3 did you update from? phpBB 3.0.5
What MODs do you have installed? shoutbox
What styles do you currently have installed? AcidTech Lime *
What language(s) is your board currently using? english
Which database type/version are you using? MS SQL Server
What is your level of experience? New to PHP and phpBB
What username can be used to view this issue? fritz
What password can be used to view this issue? 282828
When did your problem begin? even on the old 3.0.05 version it was like that
Please describe your problem. had the following issue when i sent a pm to a user
"
[phpBB Debug] PHP Notice: in file /includes/functions_profile_fields.php on line 546: gmmktime() [function.gmmktime]: Windows does not support negative values for this function
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4183: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4185: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4186: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4187: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
"
and when i veiw the top rite corner members, going to page 2 and 3