[TYPO3] IMAGE returns NULL

[Korben Dallas]

Hi folks,

I'm new to typo and to this list, and I'm a bit confused...

I'm trying to output an image from an FE plugin's class (the extension
was created using the kickstarter). As demonstrated in the nice video
made by Kasper S. (fepi_05_rendering_the_image.wmv):

    01 $imgConf = $this->conf["myImageConf."];
    02 $imgConf['file'] = "uploads/tx_myext/myimage.gif";
    03 return $this->cObj->IMAGE($imgConf);

If I understand it correctly, [01] is optional, it just loads
*additional* configuration and may be omitted. Is that so? (At least
it looks like it in the video.)

However, [03] returns NULL. The "myimage.gif" file does exist, I tried
both absolute and relative paths, and if I replace

    03 return $this->cObj->IMAGE($imgConf);

with

    03 return "blah blah blah";

this "blah blah blah" does appear in the frontend.
    
What am I doing wrong? Do I have to enable anything or something?

Thanks in advance for your help.
 
Cheers,
Korben