Making Transactions Work - Without Blocking

I'm having a very difficult time getting any type of transactions to work without encountering blocking.

Here's what I have. I created a package using the Import data option on a database to start with. That gave me the following:

On the control flow tab there is a Preparation SQL task which truncates a table followed by a Data Flow Task that then copies from an oracle database into that same table.

The two are connected by the green success arrow.

For obvious reasons, if the import from oracle fails, I would like the truncate of the table to be rolled back so that the table in question is returned to its previous state.

I have tried the following:

Setting the transactions setting on the data flow panel to "supported" and changing it on the Control Flow tab to required.

Setting both to required.

Setting the data flow setting to "supported", then adding a sequence container onto the control flow panel, moved both the preparation and data flow tasks into it and then set the sequence container to "required".

In all cases I have installed the package onto the server and then scheduled a job in SQL Server agent to run the package.

No matter what way I do it, the preparation sql task apparently opens a transaction and then the following data flow task starts a different one and is blocked by the first one. If you check a log file I set it to generate it clearly gets stuck after the sql preparation job when trying to start the data flow task. Checking sql server itself (Activity monitor), the job is stuck because it is blocked by process "-2".

So I'm lost as to how to make one single transaction be used for the entire package and get the behavior i need....

Thx.

R-