Microsoft chart images are not loaded from MOSS server

Question

hi,

i have webpage in which a webpart contains a Chart control. the problem is chart control is rendered perfectly when i login as central admin. but when i login as another user with contribute permisson following problems occur.

1. when i change webconfig as --- add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\TempImageFiles\;"---

   page is not at all loaded. i get error like YOU ARE NOT AUTHORIZED TO VIEW THIS PAGE.

2. when i change the wbconfig as --- add key="ChartImageHandler" value="storage=memory;timeout=20;URL=/_layouts/Images/MicrosoftChartControls/" ---

the page loads fine but image is not rendered. A red mark appears in place of image.

I tried all optins got by googling.. any more suggestions/help will be welcomed