The ADP fails as is - if I want to change age/service to 21/1 year and then run the test - can I if one of the newly eligibles for '06 based on the 'no service' requirement is an HC? He deferred the maximum. I've never run in to this before - so, do I change the requirement to 21/1 but keep the HC in the testing? Thanks in advance...

you are not changing anything. (at least I hope)
when you run the ADP test you can test everyone together, or test otherwise excludable employees separately from those participants who are statutorily includable.
thanks to SBJPA you are also allowed to 'pretend' that all HCEs are statutory includable, even if they haven't worked a year (12 months, completed 1000 hours) or are age 21.
Usually this would only pertain to owner's kids, as it would be uncommon for someone to have been recently hired and make $$$$$$$$$$$$ in the prior year.