I'm using a Gmail account and in the Folders section that I mentioned, for me all of the server folders are listed, such as Inbox, Drafts, Sent Mail and Spam. So I'm not sure why you're not at least getting the server folder list.
I remember an issue recently with the K9 email client where the IMAP folder list could not be retrieved if the app had been installed on external storage. So if you are using a custom firmware, such as CyanogenMod, it might be worth checking that you have not told it to install all apps on the external SD card, if you have one.
Regards,
Jacko