Drupal 6.19 - cannot add node links to primary-links I have a problem that is driving me crazy. I've been trying to solve it for a week now without luck.
The problem is, I can't add any internal (node/xxx) links to primary-links. After I add one, it appears, but I cannot edit or add any nodes until I delete that menu item. If I try to edit a node, i get the message "username admin does not exist". It looks like this triggers an effect that is causing admin user to lose permisson for node_access. After I delete the created menu item, everything is back to normal... until I add another menu item.

Here's a summary:


I can add external links to primary-links, no problem
I can add internal links to seconday-links, no problem
It doesn't matter if I add the menu item manually or by specifying one on the node edit page, the effect is the same
The language, weight and position of the menu item doesn't matter, as long as I add an internal link to primary-links, the above problem appears
I tried to rebuild the menu, disable modules, clear the cache, rebuild permissions, no luck
I double checked the menu_links table, there were some orphan items (had no parents) which I deleted, but otherwise everything is fine


I am using Drupal 6.19 with only one user (the admin), a bunch of modules and 11 languages. I must solve this problem soon as we need to add another language and it'll definately need some internal links in the menu.

Edit: Here are the modules currently enabled:

CCK


Content   6.x-2.8
Content Copy  6.x-2.8
FileField 6.x-3.7
FileField Sources 6.x-1.2
Node Reference    6.x-2.8
Number    6.x-2.8
Option Widgets    6.x-2.8
Text  6.x-2.8


Location


IP to Locale  6.x-1.0-rc1 
Smart IP  6.x-1.3


Meta tags


Nodewords 6.x-1.11
Nodewords - basic meta tags   6.x-1.11


Multilanguage


Block translation 6.x-1.7
CCK translation   6.x-1.7
Content type translation  6.x-1.7
Internationalization  6.x-1.7
Menu translation  6.x-1.7
String translation    6.x-1.7


Other


Custom Page   6.x-1.17
Custom Page Admin UI  6.x-1.17
GeoIP 6.x-1.4
Global Redirect   6.x-1.2
Menu attributes   6.x-2.0-beta1   
Menu breadcrumb   6.x-1.3
Page Title    6.x-2.3
Path redirect 6.x-1.0-rc2
Token 6.x-1.15
Webform   6.x-3.14


I can provide any information if you can help, just ask!

Thanks in advance
Issue solved.

Looks like that with the large menu tree, Mysql packet size was exceeded.

I just added the following to mysql config (my.ini) and the issue resolved:

[mysqld]
max_allowed_packet = 16M