Drupal 7.x

I have created a few nodes and made reference to a hierarchical "main menu":

Home
---About
------Team
------Contact
---Products
------Fruit
------Meat

When I add the "main menu" block to the sidebar (on admin/structure/block), this menu appears as it should. However, if I put print_r($main_menu); in my page.tpl.php file, it returns an empty array!

This is driving me nuts. Why is the $main_menu array empty?

I just installed d7 alpha 4, I could not see option for 'ANONYMOUS COMMENTING' option. In D6 it's in the 'Content Type' > 'Comments Settings'.
I checked it in the 'permissions' page also. Where did it go?

Thanks, Noussh.

In our module there is a chance to upload attachment to a report. However this file upload does not work - it just gives this error message when submitting form:
The file could not be uploaded, because the destination sites/default/files is invalid.
File system has been set to public, destination directory exists and is writable.
This is how I try to upload a file:

I want to install drupal version 7 alpha 4 , and in this case I found something difficult like this warning message :
Fatal error: Class 'PDO' not found in C:\mywebsites\drupal7\includes\database\database.inc on line 178

How can solve this trouble in this ???

Does anybody know of any modules that allow people to upload their own stuff?

For example, let's say I want a slideshow on my front page, I only have the pictures I want, so I will need something that upload the pictures to the server, creates/edit a file with the file names and location (probably a xml file) and display them wherever I want (or creates a block that can be called from a panel page)

Thanks.

I just installed Drupal 7 and Wysiwyg with CKEditor. CKEditor is not showing up when adding new content. I did the same for Drupal 6 and it worked like a charm. Is there something I'm missing for Drupal 7?

I'm rather new at all this. I looked through the forums and all and didn't find any answers.

Caryl