This is probably going to sound insulting, but could you try one last thing for me?
1. Set the CSS Mode TV to CHUNK, making sure there are no spaces before or after and no quotes.
2. Set the CSS File TV to the name of your chunk, again with no spaces or quotes
3. Save the resource
4. Edit the chunk and paste in the name you used in the CSS File TV, again with no spaces or quotes.
5. Save the chunk
6. Delete all the files in the core/cache directory.
I'm almost positive that there are people using the CHUNK option successfully.
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PLEASE, PLEASE specify the version of MODX you are using.
MODX info for everyone:
http://bobsguides.com/modx.html