help getting rails application working on fastcgi

Hi,

I've previously had a rails application up and running on dreamhost using fastcgi, however have just recently performed a "cap deploy" but have had problems:

* I get a long wait period after browsing to the application and finially it returns "Application Error - Rails application failed to start properly"
* No entries in the rails production (or development) logs
* No fastcgi.crash.log entries
* In the /log/http error.log I see "FastCGI: incomplete headers (0 bytes) received from server "
* If I run dispatch.rb
[skybar]$ ruby dispatch.rb
./../config/environment.rb:3: uninitialized constant RAILS_ROOT (NameError)
from dispatch.rb:4:in `require'
from dispatch.rb:4

Can anyone help with some fault finding tips re how to track down whats going wrong?

Note that I have made sure:

* log/temp & dispatch.fcgi are writeable
* have issued "killall -9 ruby"
* etc

Thanks in advance
Greg

PS. I did not that in ~/logs/<domain>/http/error.log there are the follow 2 entries that show up after a timeout period of the browser not returning correctly:

* FastCGI: comm with (dynamic) server "<domain>/public/dispatch.fcgi" aborted: (first read) idle timeout (120 sec)

* FastCGI: incomplete headers (0 bytes) received from server " <domain>/public/dispatch.fcgi"

Does this help? Anyone know how to fix this?