I found this scenario interesting, so I thought I'd ask.
I answered a question posted on the webapps site: https://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: 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.