Related Document Problem

[mario.gamboa]

When i try to Related Document in a create document module show me a windows that say

ERROR CONNECTING to http://mydomain.local/json_server.php, ERROR: not well formed


but the document is related in the document created when i try to see the document releated is show me
Notice: Undefined property: name occured in /var/www/html/sugar/modules/DocumentRevisions/DetailView.php on line 74 [2006-06-08 13:09:47]
[L:](:stacktraceerrorhandler)
/var/www/html/sugar/modules/DocumentRevisions/DetailView.php[L:74](:unknown)
/var/www/html/sugar/index.php[L:630](:include)

is a bug or something is wrong

OS Linux Redhat Enterprise 4
Softtware
[Sugar Version]
Sugarcrm 4.2d
[Mysql]
mysql-4.1.12-3.RHEL4.1
libdbi-dbd-mysql-0.6.5-10.RHEL4.1
mysql-server-4.1.12-3.RHEL4.1
mysql-devel-4.1.12-3.RHEL4.1
mysqlclient10-3.23.58-4.RHEL4.1
[PHP]
php-4.3.9-3.12
php-pear-4.3.9-3.12
php-ldap-4.3.9-3.12
php-imap-4.3.9-3.12
php-mysql-4.3.9-3.12
[Apache]
httpd-2.0.52-19.ent
httpd-suexec-2.0.52-19.ent
httpd-manual-2.0.52-19.ent
system-config-httpd-1.3.1-1