[eluser]Henrik Pejer[/eluser]
I've been looking into the code for the transactions in CodeIgniter and it would seem as though CodeIgniter does not have its own system for handling transactions, but rather uses whatever transactions your database implements.
If you are using MySQL trans_begin is the same as running the following queries:
Code:
SET AUTOCOMMIT=0;
START TRANSACTION;
So it would seem that if your database does not support transactions, depending on the type of database (mysql, postgre etc) and version, transactions might not work.
I'd check what version of database you are running, and then try to see if you can use transactions when you are not using the transaction code included in CodeIgniter.
If it works 'outside' CodeIgniter then something is wrong, otherwise it seems to be a problem with your database and/or version.
I hope you are able to solve your problems, good luck!