"cannot start a transaction within a transaction" sqlite err

I’ve been editing a rails app on Windows for a little while now. I
just checked it into source control and started editing on my iMac.
Everything seems to run normally, except that when I attempt to modify
the database in any way (I’m running sqlite), I get a weird error:

“cannot start a transaction within a transaction”

/usr/local/lib/ruby/site_ruby/1.8/sqlite/resultset.rb:71:in compile' /usr/local/lib/ruby/site_ruby/1.8/sqlite/resultset.rb:71:incommence’
/usr/local/lib/ruby/site_ruby/1.8/sqlite/resultset.rb:65:in initialize' /usr/local/lib/ruby/site_ruby/1.8/sqlite/statement.rb:104:inexecute’
/usr/local/lib/ruby/site_ruby/1.8/sqlite/database.rb:194:in execute' /usr/local/lib/ruby/site_ruby/1.8/sqlite/database.rb:571:intransaction’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/connection_adapters/sqlite_adapter.rb:171:in
begin_db_transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/connection_adapters/abstract/database_statements.rb:48:intransaction’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/transactions.rb:91:in
transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/transactions.rb:118:intransaction’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/transactions.rb:126:in
save' #{RAILS_ROOT}/app/controllers/message_controller.rb:29:increate’

I don’t get this error on windows. Has anyone seen this? If so, does
anyone know of a fix for it? I’m running the latest stable version of
rails on both machines.

Thanks,
Carl