PHP Fatal error: Cannot use string offset as an array

[lkoumis]

I got this error when I tried to upload a document for the first time. I didn't touch the classheaders.php file.

I am using Mysql 5.1.34 and php 5.2.9-2 on iis7.

error:
PHP Fatal error: Cannot use string offset as an array in D:\wwwroot\dms\classHeaders.php on line 53
suggestions?

thank you.