Try turning off the compress_css and compress_js System Settings.
Then, try deleting all files in the core/cache directory, clearing your browser cache and cookies, then running Setup.
If that doesn't do it, maybe the category of the templates doesn't exist. I know that will keep property sets from showing up in the grid and maybe it affects Templates as well. You can look at the modx_site_templates table in PhpMyAdmin, check the category field, and see if a category with that ID actually exists in the Elements tree in the Manager.
Another possibility is that your date/timezone settings (modx, MySQL, PHP) don't match. That can cause problems with Templates, though I haven't seen a report of your particular problem.
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MODX info for everyone:
http://bobsguides.com/modx.html