Are you using the D6 or D7 version? I'm thinking that this should have worked out of the box by adjusting the individual block settings on the block config page, but perhaps not (block.tpl.php may require editing, I know D6 needs a specific title selector)

I am using the D6 version of the theme.

Try this alternate version of block.tpl.php. You may need to clear the cache.

The code you provided seems to have worked ... kind of. I can now create collapsible block in all the regions, except now I cannot turn off or disable that functionality in those regions. In other words, sometimes I want collapsible content and other time I don't want that.

I've also noticed something else really weird. I placed a views form into a collapsible block. When I close this block, blocks close on my front page in all regions except for the left and right sidebars. When I go back to views form and open it, the block on the front page open, too.

I'm puzzled. It's like the collapsiblock module cannot tell the difference between all the blocks.

Hey - sorry for the wait on this, I've been bogged down putting the finishing touches on this month's theme release. It'll be released tomorrow and then I should be able to take a closer look at this problem.