I found this scenario interesting, so I thought I'd ask.
I answered a question posted on the webapps site: http://webapps.stackexchange.com/questions/9922/free-asp-net-ms-access-support-webhosting-closed
I checked back in a short time later and noticed that the question was closed, my answer deleted, and the question migrated to the webmasters site: http://webmasters.stackexchange.com/questions/6203/free-asp-net-ms-access-support-webhosting
The question on the new site had my name in the answer, but no link to the profile (I'm assuming it was treated as an anonymous answer). Since I had never been to the site before, I went ahead and logged in, linking up my S[OFUM] profile to the account.
Now that I'm registered, is there any way to "claim" this answer? I'm not too worried if I can or cannot claim the answer, but I'm wondering how often this is occurring now with the ever expanding and migrating of sites/questions/answers.