Hi Robin,
I am using QB 4.0.1
The node selection doesn't work properly.

I have 2 view server vob1 + vob2
vob1 has the User Attributes : VIEW_SERVER=vob1 and vob2 VIEW_SERVER=vob2
In my configuration I have a variable viewServer
In the 2. Step I read the viewServer from our database and set the viewServer vars.get("viewServer").setValue(viewServer).

In a script I show the value of viewServer

logger.info('### Start viewServer = ' + vars.getValue("viewServer"))

after it is set I show the value again.

logger.info('### viewServer = ' + vars.getValue("viewServer"))

See the output below.
12:50:43,564 [master>parse@smd-control.ger.magma.lan:8810] INFO  - ### Start viewServer = vob1

12:50:44,255 [master>parse@smd-control.ger.magma.lan:8810] INFO  - ### VIEW = lti_magma5.1
12:50:44,255 [master>parse@smd-control.ger.magma.lan:8810] INFO  - ### viewServer = vob2
12:50:44,255 [master>parse@smd-control.ger.magma.lan:8810] INFO  - ### PLATFORMS = WIN64_XP,WIN32_XP,LINUX64_25,LINUX_25

If I want to run a step on the viewServer a wrong value is taken. I think is the intit value.

On node with specified script evaluating to true
groovy:
node.getAttribute("VIEW_SERVER") == vars.getValue("viewServer")

This step should be run on vob2.ger.magma.lan but it runs on vob1.ger.magma.lan
See output below:

13:16:00,541 [master>check for checkouts@smd-control.ger.magma.lan:8810] INFO  - Checking step execute condition...
13:16:00,542 [master>check for checkouts@smd-control.ger.magma.lan:8810] INFO  - Step execute condition satisfied, executing...
13:16:01,627 [master>check for checkouts@vob1.ger.magma.lan:8811] INFO  - Executing pre-execute action...
13:16:01,628 [master>check for checkouts@vob1.ger.magma.lan:8811] INFO  - ### viewServer = vob2
13:16:01,628 [master>check for checkouts@vob1.ger.magma.lan:8811] INFO  - Running step...

With OB 3.1 it works, and select the right node.