str_replace just returns caps

[kanchetty]

i have a lil problem here..i'm using \[code\]str_replace\[/code\] to replace the most common words..and for some reason its replacing every letter except caps.for example..if i had the code below\[code\]$str ="Fat string of Text."; $commonwords = array('fat','of','random');$cleantext = str_replace($commonwords,'',$str);\[/code\]\[code\]echo $cleantext;\[/code\]it would echo.. \[code\]F T\[/code\]any ideas what i did wrong..thanks in advanceand oh..i tried \[code\]str_ireplace\[/code\].. but nothing