I've installed DirectPHP_v1.54 for jommla 1.5.3
It installed with no problems. Enabled the plugin.
Tried with the following example: Current date and time is: <?php echo date('Y-m-d H:i:s');?> with JCE 1.5.0 editor.
I just get Current date and time displayed in the page.
Can someone help me , find out what the problem is.
Note: the following plugin is also installed and enabled
DirectPHP for Section/Category Description. I don't know if this is part of the problem. I'm new the joomla.

First, please change the editor back to the default TinyMCE WYSIWYG Editor.

Remeber that you have to enter the php commands in WYSIWYG mode, not HTML (or source) mode.

This will allow you to know if DirectPHP works on your system at all. If it works, then we can narrow the cause to the JCE 1.5.0 editor.

If it doesn't work, then please describe the steps you have taken and what you've tried. I need more clues to be able to guess what might be the problem.

Regards,
/kksou

I tried what you said by changing the editor to the default
WYSIWYG, also entered the php commands in WYSIWYG mode still does not work when I preview the page I get the following output: Current date and time is: <?php echo date('Y-m-d H:i:s');?>
Also, tried the above steps by changing the editor to TinyMCE 2.0, still does not work I get the same output: Current date and time is: <?php echo date('Y-m-d H:i:s');?>. When I enter the php command in the WYSIWYG mode a red dotted line appears under the word php. This is what I get when I look at the HTML source mode: <pre>Current date and time is: &lt;?php echo date('Y-m-d H:i:s');?&gt;</pre> <p>&nbsp;</p>.
I hope these clues are enough for you to find out what the problem might be.
Thanks.