Upgrading Drupal

Dear all,

I'm using Drupal 6 and i have a problem with numbers in Drupal.
I've been trying to change the numbers in English to Arabic format
for example i wanna change 2/3/2011 to ۲/۳/۱۳۲۲ in publish date in all around the website.

your help would be greatly appreciated!
Thanks in advance

So our developer has upgraded the back-end from 7 > 7.4, but in doing so this causes all sorts of issues w/ trailing slashes that weren't a problem in 7.0. Anyone have any idea why this breaks Drupal? ie: mysite.com/user worked fine in 7.0, but doesn't resolve in 7.4 to the admin page... We've played around with .htaccess, but that inverts the problems: on urls that worked, they break & vice-versa... Server environment has both 7.0 version & 7.4 version running in separate vhosts, so they're isolated. And I know I'm not the first person to run 7.4 under SuSu11...

Can anyone help me, I got this notice:
Undefined index: highlighted in include() (line 120 of /home/xxx/public_html/modules/system/page.tpl.php).

what can I do about it?

Hope this is the right thread..
It's just something I wonder anyway
Ive used 6.22 and 7.4
When I compare the SQl database Ive noticed 6.22 has a way smaller cache_menu value
I think it's less than a MB.. where as 7.4 goes over 1 MB
What impact or differences does this create?

I am optimizing a Drupal site for a client who recently updated their website to Drupal version 7. I am not that familiar with Drupal but I was able to install and use the plugin page_title prior to their update.

I have installed the page_title module that matches the new drupal version 7 and i have configured the module in the adminster link, but it does not show up when i edit the pages when i am in site.com/user.

This now appears 4x on each page, 2x on each node edit page. Any ideas?

warning: Missing argument 2 for theme_menu_tree() in [site]\includes\menu.inc on line 1141.

I've disabled all blocks & block menus, turned off primary menus, to no avail.
ETA: also tried changing to Garland theme, but that didn't stop the errors.