The current SVN head of file-roller in src/fr-command-7z.c at line 98 looks for the text "--------" at the beginning of 7zip output before parsing the rest of the output. My copy of 7zip (4.43) doesn't actually output this text and so all 7zip archives seem to be empty in file-roller. Output for a command typically used by file-roller is as follows:

tparker@shostakovich:[~/data/src/file-roller] 7z l -slt -bd -y -- "/tmp/Fixing Hard Problems Through Iterative QA and Development Presentation.zip"

7-Zip 4.43 beta  Copyright (c) 1999-2006 Igor Pavlov  2006-09-15
p7zip Version 4.43 (locale=en_GB.UTF-8,Utf16=on,HugeFiles=on,8 CPUs)

Listing archive: /tmp/Fixing Hard Problems Through Iterative QA and Development Presentation.zip

Path = oscon2008-QA-Leak-Testing-latest-slides.odp
Folder = 0
Size = 864544
Packed Size = 740546
Modified = 2008-07-24 12:09:22
Attributes = .....
Encrypted = 0
Comment = 
CRC = 9116B727
Method = Deflate
Host OS = Unix



This is the default version of 7zip on a Ubuntu 7.04 system, and I think that the correct text that should be matched in this case is probably "Listing Archive".