I tried some fiddling around but I don't see why my opera 18 is having trouble reading opera 12 profile ?
the folder for opera 18 is in appdata/roaming/opera software
and for opera12 it is appdata/roaming/opera

and both are 32 bit.

so I still don't get it that why is opera 18 not reading through the old profile.
and where is that one single bookmark of bing.com coming from ?

I think if I can find the location of that bing bookmark I may find the source of trouble.