I have a few domains which have backlinks in authority sites but for some reason they dont get indexed in Google.
I have Googled for an answer but havent found anything useful so far.
Please let me know if anyone can help me/has some ideas.
This may sound stupid, (partly because it is), but build additional links to these links (if viable and worthwhile) so that Googlebot can discover these new links.
However, in the two years since you posted this question I hope your SEO activity has moved beyond scoring links on Flickr!