Unsupported file format (SQLite3)

I’m running sqlite3-ruby 1.1.0 and sqlite 3.3.4 on 2 linux machines. I
create a (small, single table) database on 1 machine, and I can re-open
it and work with it fine on that machine.

I copy it over to the other and can do:
zdb = SQLite3::Database.new( zf )
but then it crashes on the next line:
z = zdb.execute(“select * from Data”)
with:

/usr/local/lib/ruby/site_ruby/1.8/sqlite3/errors.rb:94:in check': unsupported file format (SQLite3::SQLException) from /usr/local/lib/ruby/site_ruby/1.8/sqlite3/statement.rb:70:ininitialize’
from /usr/local/lib/ruby/site_ruby/1.8/sqlite3/database.rb:183:in
prepare' from /usr/local/lib/ruby/site_ruby/1.8/sqlite3/database.rb:210:inexecute’
from f.rb:9

The sqlite3 cl tool handles it fine, so does Mono.

Any help much appreciated.