Possible bug when using £ sign

Hi,
I've used a £ sign in a default markdown page. On the first save, the £ sign appears fine on the webpage.
When I go back to edit this file, a à character has been placed in front of the £ sign. This ‚ sign appears on the webpage.
When I go back edit this file again, there are more à signs in front of the £ sign and they too appear on the webpage.
None of this happens for the $ sign.
Cheers,
Luke

Are you saving the file in UTF-8 format?

Not that editor again! :(
Thanks for the tip.