We do have that header set in the load balancer as it was required for the previous mongrel setup which you have also noted. The reason we think it is something to do with Litespeed is that debugging output from the rails app does appear to show it receiving the header properly and setting the proper re-direct url. I have included some ngrep output below from the litespeed server. Thanks for the quick reply!
T client:3037 -> Litespeed server:80 [AP]
GET / HTTP/1.1..Host: admin.test.com..User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.9) Gecko/200612
06 Firefox/1.5.0.9..Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
..Accept-Language: en-us,en;q=0.5..Accept-Encoding: gzip,deflate..Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7..Keep-Alive: 3
00..Connection: keep-alive..Cookie: _session_id=543d57d3eb9eb3f80d219841981cd55f; Cookies=ON..X_FORWARDED_PROTO: https....
##
T Litespeed server:80 -> Client:3037[AP]
HTTP/1.1 302 Found..Content-Type: text/html; charset=utf-8..Set-Cookie: _session_id=543d57d3eb9eb3f80d219841981cd55f; domain=test.com; path=/..Location:
https://admin.test.com/admin..Cache-Control: no-cache..Content-Encoding: gzip..Vary: Accept-Encoding..Transfer-Encoding: chunked..Server: LiteSpeed..Date: Fri, 26 Jan 2007 23:48:29
##
######
T Client:3038 -> Litespeed server:80 [AP]
GET /admin HTTP/1.1..Host: admin.test.com..User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.9) Gecko/2
0061206 Firefox/1.5.0.9..Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;
q=0.5..Accept-Language: en-us,en;q=0.5..Accept-Encoding: gzip,deflate..Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7..Keep-Ali
ve: 300..Connection: keep-alive..Cookie: _session_id=543d57d3eb9eb3f80d219841981cd55f; Cookies=ON..X_FORWARDED_PROTO: https....
##
T Litespeed server:80 -> Client:3038[AP]
HTTP/1.1 301 Moved Permanently..Server: LiteSpeed..Date: Fri, 26 Jan 2007 23:48:29 GMT..Location:
http://admin.test.com/admin/..Content-Type: text/html..Content-Length: 414....<html>.<head><title> 301 Moved Permanently..</title></head>.<body><h1> 30
1 Moved Permanently..</h1>.The document has been permanently moved to <A HREF="%s">here</A>.<hr />.Powered By <a href='http://w
ww.litespeedtech.com'>LiteSpeed Web Server</a><br />.<font face="Verdana, Arial, Helvetica" size=-1>Lite Speed Technologies is
not responsible for administration and contents of this web site!</font></body></html>.