Like most hosting companies, at aegis we use the mod_security apache module to prevent hackers and automated scripts from maliciously affecting our servers and your websites.
With MODx this can throw up a couple of problems as we may block submission of some forms in MODx if mod_security thinks the content being submitted is malicious and matches one of the patterns in our ruleset.
The MODx wiki has a good description of how best to work around mod_security at http://wiki.modxcms.com/index.php/What_is_mod_security_and_how_does_it_affect_me
We can also tailor our mod_security rules should you still be unable to get around any form submission issues. Please raise a support ticket detailing your issue and let us know which URL your're having issues with.
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