Rails - Jan 2006 - "cannot start a transaction within a transaction" sqlite error on OS X Tiger but not Windows

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:in `commence''
/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:in `execute''
/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:in
`transaction''
/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:in
`transaction''
/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:in
`transaction''
/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:in `create''

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