I have successfully installed the robots-meta plugin. It has written an .htaccess file -- but the file is the default settings from the initial install of the plugin. I can select (and unselect) any boxes that I wish, but none of them actually alter the code in the .htaccess file.
I initially thought it might be an issue with directory write permissions -- however, that should not be an issue as the plugin was able to write the default .htaccess file. The problem is that the plugin is not altering that default file to reflect my checked options.
Any assistance is greatly appreciated.