error log: recursion detected xpdo

The site loading time on the front-end is extremely slow, the error log is full of errors:

[2011-05-03 11:55:51] (ERROR @ /domains/website.com/DEFAULT/sub/core/xpdo/xpdo.class.php : 1931) PHP warning: json_encode() [<a href=’function.json-encode’>function.json-encode</a>]: recursion detected

Is it possible that the extremely long load times on the front-end have something to do with the errors?

MODX Revolution 2.1.0-rc4 (traditional)
PHP: 5.3.6-6~dotdeb.0
MySQL: 5.0.87-d10-ourdelta65-log

PDO Driver for MySQL: mysqlnd 5.0.8-dev - 20102224 - $Revision: 308673 $
PDO Driver for PostgreSQL:
-PostgreSQL(libpq) Version 8.3.14
-Module version 1.0.2
-Revision $Id: pdo_pgsql.c 306939 2011-01-01 02:19:59Z felipe $

This has nothing to do with xPDO—it is a known error with the use of the JSON methods in xPDO by an Extra, most likely the tinymce Extra.

Youre right it was TinyMCE, thanks for the mention!