Problem with Blocks management

Hello

I have a new installation of Commons and am also a new user of Drupal.

I would like to change the block configuration and add blocks to various pages. I go to Administer > Site Building > Blocks and can add blocks to where I want them. However, I cannot move them up or down. It is clear to me that Commons is pre-configured but it is also clear that I can add new blocks and, perhaps, change the default layout.

In positioning my new blocks, I need to be able to access the weight of each block. However the weight dropdown box does not appear. Actually it does appear and quickly disappears. Because I am on a slow connection (I am in Thailand) and the list of blocks is very long, I have actually been able to change the weights of blocks by changing them as the page loads and before the weight column disappears. While this solution works, it is not very satisfactory - and will disappear once I am on a faster connection. I cannot seem to adjust the weight of a block anywhere else.

So... how can I get the weight box to appear permanently in the blocks configuration page?

Thanks for any help
Andrew