Hi:
Personally, I can only tell you that my SAS 8 code ran successfully in SAS 9 without needing any changes. However, most of my code is limited to Base SAS procs: REPORT, TABULATE, FREQ, MEANS, UNIVARIATE, PRINT, SORT, DATA step, Macro, SAS/Graph procs and a few STAT procs -- REG, SURVEYREG, GLM, PRINCOMP.
However, this is exactly the kind of question you should ask of Tech Support.
cynthia