Look at this code:

         function strhex($ni) {
           $ni=dechex($ni);
           while (strlen($ni)<2) $ni="0".$ni;
           return $ni;
         }

         $color=strhex($r).strhex($g).strhex($b);
         echo $color;

it works fine if nothing else in a file :(
I have one file using that code that's not working under PHP4, but works great under PHP3. (same server, different port) :(((

so I tried

              $color=strhex($r);
              $color.=strhex($g);
              $color.=strhex($b);

instead the last line and it worked fine. I could'nt find any error, so I thought this may be interesting 4 you (whether I know this error - if it is one - might be hard to find and the description is)...

I also tracked that variables... the function calculates the correct value (e.g. "9b") every time, but the 3 values are not concated in the right way (its running in a loop, any second cicle all values are calculated correct, but I only get "9b9b" instead of "9b9b9b"; the other cicle everything is OK)

PHP(4) is compiled using the standard settings with the latest apache stable (.12) and mysql.libs

sorry for my english & stay tuned
  Lars