Activation failure

I have been using Better WP Security for some time now on my site. I have recently moved my site from GoDaddy shared hosting to VPS at Interserver.net. In the process, I transfer my MySQL DB across, do a clean install of WP v3.8, ftp in any media, login as an administrator and do a clean install of the plugins. This has worked perfectly on several sites, except for one case of Better WP Security. The plugin will install but it will not activate. There is no error. It is just that the installed plugins screen shows the plugin present but not activated. If I attempt to activate, I get a success indication; however, the plugin continues to show up as not activated.

The plugin has succeeded on several other sites with the same list of other plugins. I have removed its entries from .htaccess and dropped its tables from the MySQL DB. This seems to make no difference and the installation rewrites these items anyway.

Still, activation fails. Any suggestions?

http://wordpress.org/plugins/better-wp-security/