error log file not wirking

OK, I'm running 4.0.5 on windows 2000. I put a file phperror.log in my php folder and then set my php.ini to these settings: display_errors = Off log_errors = On error_log = D:\PHP\phperror.log ;error_log = syslog (commented) But it's not working. I have write permissions for admin on my errorlog file so that's not it. But nothing is writing to the file, instead it is appearing on my output pages at the BOTTOM instead of at the top where it normally does if you have display errors on. Any ideas? Thanks!