I have been trying a few themes, and had problems changing the default headers, as per this thread: http://wordpress.org/support/topic/twenty-ten-header-image-problem-changing
so decided upon Mantra but I still cannot insert a header - this time even the default. This is not a major issue as I thought I could insert images lower down, but I actually can't insert any images at alL!
The images currently on the site are ones that were uploaded when it was a different template...
I know the obvious solution is to revert to another template, add images and get back to Mantra but reluctant to lose all my modifications.
Any advice gratefully appreciated!