The plugin is redirecting both the Googlebot and Yahoo Slurp, but is not damaging the MSNbot’s page crawling.
What’s happening there is Googlebot is requesting my homepage, getting a 302 redirect for /wp-mobile.php, and then a 404 not found for that file. In my stupidity I didn’t copy across the file in question as per the installation instructions (although I’m not sure why the plugin doesn’t simply redirect to the plugin folder?).
So you can see how Google was getting those 404 errors. But my stupidity aside, there is a very nasty flaw in Ruadhan O’Donoghue’s plugin: mobile content is served to search engine robots.
If you serve excerpts for each post on your homepage then you really want the Search Engine bots to see that content. Granted, my own cock-up added to my issues by serving 404’s to the bots, but I think the plugin will need some modification to ensure that regular web-crwalers aren’t getting the minimal content that mobile devices get. For actual post pages this isn’t really an issue, but for the homepage this plugin could really affect your rankings - I for one need to ensure that my homepage is served correctly to the bots.
Source:→ SEJ BlogMobile WordPress Plugin, WordPress Plugins, Google Ranking, Google Bot