Trouble Updating Domain Mapping Plugin

Howdy all,
I'm having a little trouble updating the domain mapping plugin.
I've uploaded the new verison but it's still telling me I need to update.
Tried having it in mu-plugins and the plugins folder with no success.
Wondering if this is just WP getting confused and not seeing the update or something else.
About to test mapping a domain so will know if its still working after that I guess :S
Cheers,
D