Curl::Err::HostResolutionError (Couldn't resolve host name)

I'm running Rails 3.0 with a custom Devise authentication strategy that makes an SSL call using Curb. I get an "Curl::Err::HostRes开发者_开发百科olutionError (Couldn't resolve host name)" error. Works fine manually from the command line.

The production environment is Apache running Passenger standalone with rvm 1.9.2@rails3, because the main Passenger is running ruby 1.8.7 and rails 2.3.4. I don't get this error with the my other app running the earlier versions of ruby and rails. Same code, but the difference seems to be Devise.

I've read elsewhere that this might have something to do with DNS and Apache, but I can't for the life of me figure this out and I'm really grasping at straws here. Any ideas would be greatly appreciated! Thanks in advance!

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The issue actually turned out to be related to user permissions. When I ssh in with my user account and start Passenger standalone, no problem. When I start it remotely from Capistrano with the deploy user I get the error.