Upgrading Drupal

I am upgrading a Drupal 5 site to 6 and I am having problems.

I have brought the database over to a test sandbox and for the most part it works except;

Despite having setup the profiles in much the same way having imported them into the new Content Profile module, keeping all the same settings etc and setting the Automatic Node titles but when I try to view a profile Firefox tells me

How to upgrade from 6.13 to 6.15 please guide the process

Last checked: 0 sec ago (Check manually)
Drupal core
Security update required!Drupal 6.13
Recommended version: 6.15 (2009-Dec-17) Download Release notes
Security update: 6.15 (2009-Dec-17) Download Release notes
Security update: 6.14 (2009-Sep-17) Download Release notes

How to update the new verison in my site i wanna update from 6.3 to 6.5

I just upgraded fckeditor to 6.x-2.0 from 6.x-1.4. I also upgraded the base fckeditor code to version 2.6.6. Now, in firefox, my toolbar is messed up. I only see a bit of text and no icons. However, everything looks and works fine in IE 8. Version 2.6.6 is really new and I wonder if it is compatible with the drupal module?

Fatal error: Only variables can be passed by reference in /home/XXXXX/public_html/sites/default/modules/admin_menu/admin_menu.inc on line 521

I just upgraded from 6.10 to 6.15... What is that? It happened to me when I clicked on save-like stuff.
Like, save configuration for modules/themes, yet the changes seem to take place after all...

I have installed drupal 6.15 and enabled path and pathauto. But now a quite a few days back, the pathauto has stopped working.

But an url alias is been created but it doesn't show up. It shows me as www.yourdomain.com/node/1234 instead of the www.yourdomain.com/url-alisas.html.