lucy24 - 11:50 am on Aug 17, 2011 (gmt 0)

[Wed Aug 17 03:50:49 2011] [error] [client 66.249.72.20] File does not exist: /home/risingde/domains/example.com/public_html/404.shtml

Do you get the impression your htaccess is laughing at you? :) For a while, I had the yandexbot actively asking for the 403 page in one directory. But that

/home/risingde/domains/example.com/public_html/home

is obviously wonky. That's why I asked about a RewriteBase.

I was going to say that since your directory structure is different from mine, it wouldn't be useful to try your exact wording. But I tried it in my under-construction site (where no harm is done if there's a 500-level calamity) and holy cow, I get the identical pattern: if I request

http://example.com/Forums/foobar.html

I get the 404 page at

http://example.com/home/{username}/example.com/forums/foobar.html

All for the want of a lowly slash: change the rewrite to

RewriteRule ^Forums/(.*) /forums/$1 [R]

and it plays nice. Apparently my host supplies the domain name; results are identical if I do the full

RewriteRule ^Forums/(.*) http://example.com/forums/$1 [R]

That is to say, they are identical after I whap myself upside the head and replace "example.com" with the real domain name