I noticed that when I get new links, some of them take ages to appear in the search engine backlink record and some appear very quickly. Any idea what the reason might be? It certainly doesn't seem to relate to the amount of traffic the site with your link on gets and doesn't update when the search engines update the cache of that page and thus recognising you have a link on that page either..
If site has rss feed they seem to update links faster and page rank might make links show up faster also.
The stronger the backlink generally the faster it will show up. Just because two sites are PR5 doesnt mean they have the same weight. Also Pagerank is about 3 months old now and things change, so the green bar isnt a perfect indicator. Theres far better ways to determine link weight.
Its not nessesaraly pr but content, if you update often then g comes more often and index's the links a little faster then others. "usually"
it's related the power of your backlinks. if you have backlinks which has pr 7 pages, the cache of the page which your link stays will be refeched in a short time