Task Sequence Multiple Application Install Failure

[Greg]

I have been having a lot of difficulty trying to install mulitple
applications using task sequences. I can't even setup the installation of 1
application via task sequence >Install Software>Install multiple
applications....

When I create a task sequence using "Install a single Application"
everything works fine.

At the moment I am trying to install 7-zip (easy app to start with, having
issues with many more). I have set it up as follows:

Under the Task Sequence Editor I have created a "Set Task Sequence Variable"
Task Sequence Variable:C001
Value: HQ100010:7Zip Installer

Install Software:
Select - Install Multiple Applications
Base Variable Name = C

When the sequence is in this order:
Set Task Sequence Variable, Install Software
The installation fails with Error 80004005

When the sequence is in this order:
Install Software;Set Task Sequence Variable
Nothing happens

The log files are cryptic (is there a log parser available) and I don't even
know which ones I should look into...

Again, using the "installing a single application" works great

Any help will be GREATLY appreciated!