Dropped from index with error 501

[Robert Thivierge]

I paid Lycos-InSite to include some pages of mine in the FAST/AllTheWeb index. After working ok for a while, the pages were dropped from the index, and when I asked what happened I was told the following (which I edited before posting here).

...getting a server error for this page. Although the web site URL
can be pulled up in the browser, wget yields this:

[crawler@psprdcrw001 logs]$ wget
[domain.com...]
--14:41:20-- [domain.com...]
=> `FileName.htm'
Resolving domain.com... done.
Connecting to domain.com[209.171.43.28]:80... connected.
HTTP request sent, awaiting response... 501 OK
14:41:20 ERROR 501: OK.

I was wandering if anybody got a similiar problem.

Possible Cause: I use virtual hosting and recently had a change done, which involved a new ip, and new Domain Name Server. The IP-propogation hasn't updated everyone, even after weeks. But I'm told the above error only applies to one page. So, maybe there is some other problem. I actually can't see any of the three pages in AllTheWeb, but I'm told the other pages are in the index ok, and will be appearing shortly (I guesse they have some sort-of mirroring system, where searches from different placees can yield older or new results).

I was hoping someone could tell me what "wgets" is, and what are typical causes of "ERROR 501". Perhaps people know what questions I should ask my web host (I switched from Netfirms to Nexx host, both owned by same company), so I can tell if they are the cause of this problem.