Hey Ole,
 
After your very help suggestions for datasource loops got things working for us, I did notice something else a bit strange.  I put in some println statements and captured some sample output to show what I mean (observe the behaviour of "adjusted netPort" when it approaches xxx9):
 
adjusted netPort: 1077
raw netport: 1008
raw iterator: 7
adjusted netPort: 1078
raw netport: 1009
raw iterator: 7
adjusted netPort: 1079
raw netport: 1009
raw iterator: 8
adjusted netPort: 1089
raw netport: 1000
raw iterator: 8
adjusted netPort: 1080
raw netport: 1001
raw iterator: 8
adjusted netPort: 1081
raw netport: 1002
raw iterator: 8
adjusted netPort: 1082
raw netport: 1003
raw iterator: 8
adjusted netPort: 1083
raw netport: 1004
raw iterator: 8
adjusted netPort: 1084
raw netport: 1005
raw iterator: 8
adjusted netPort: 1085
raw netport: 1006
raw iterator: 8
adjusted netPort: 1086
raw netport: 1007
raw iterator: 8
adjusted netPort: 1087
raw netport: 1008
raw iterator: 8
adjusted netPort: 1088
raw netport: 1009
raw iterator: 8
adjusted netPort: 1089
raw netport: 1009
raw iterator: 9
adjusted netPort: 1099

The Net Port Datasource was "finish"ed before the iterator (my current loop count) was incremented, but it seems to take another loop step to actually complete the "finish" operation.  I just figured out that I can work around this (in the simple case) by setting the outer loop's target to the inner loop's datasource loop testStep (although this won't help in the case where I need to reset the datasource before continuing on in the test case), but, does this strike you as a bit odd?
 
Cheers!
Jon