Flashing Typing Cursor out of position when typing in mac mail.

Just recently when I type in mac mail and go back in to edit a bit of text already written the cursor is mis aligned.

The cursor is 1 to 2 characters out.

In other words if I try to put my cursor at the end of a word the cursor is 1 to 2 character to the left, becomes very awkward when moving around using arrow keys.

Any ideas?