WordPress switching back to default theme by itself

Regular readers may have noticed the new look introduced last week. And if you’re very regular, you may have noticed that the theme keep switching back to the WordPress default theme by itself??

Twice the last 24 hours it has changed back to the default theme. Very strange. So if brilliantdays.com looks like it just has been set up, now you know why.

(googling “switching back to default theme by itself”…)

Update: This is getting ridiculous. I thought it would help to delete the standard theme. But then WordPress just changes the theme to the empty theme, making the whole site go totally blank for the whole night. Aaaargh. If you have any idea what this is caused by, please leave a comment here.

Update: Problem solved (I hope).