AutoCAD .NET :: Document Is Locked But Write Transactions Do Not Happen?

I open a document from a file (with read-only mode set to false).  Then I lock this document and start a transaction.

Within this transaction I delete all blocks that are named "MyBlockName", but none of them are deleted.

I also attempted editting attributes within a block, and the attribute textstring does not change one bit!

Anyways, after the transaction is committed, the database is saved, the lock is disposed, and the document is saved:

public void DoChanges(DrawingFile drawing)
{
//DrawingFile.FullName is a valid string of a full file name.
AcAp.Document acadDoc = AcAp.Application.DocumentManager.Open(drawing.FullName, false);
using (AcAp.DocumentLock docLock = acadDoc.LockDocument()) //Lock for modifying.
{

[Code]...

So, what steps must I do in order to open a document from a file name, make changes to it, then save it?

 The only thing that seems to not work here is making changes to it.