Hi:
One challenge with PROC REPORT and ACROSS variables is that if you have any COMPUTE blocks where you are computing some value for the ACROSS variable, you may need to use absolute column names (_C1_, _C2_, _C3_, etc) instead of the variable name. few examples of using absolute column names can be found on pages 82-84 of this document:
http://support.sas.com/documentation/onlinedoc/v82/techreport_p258.pdf
Also, SAS Report XML format is intended for use with Web Report Studio, primarily -- there's a chance that the PROC REPORT output is incompatible with SASReport XML (.srx) -- for example, if you are using LINE statements -- SASReport XML will not render LINE statement output created by PROC REPORT.
For more help with absolute column names and the ACROSS usage, you might wish to consult the PROC REPORT documentation or study these Tech Support notes:
http://support.sas.com/kb/10/710.html
http://support.sas.com/kb/23/978.html
This last note shows how to programatically figure out the number of absolute columns there would be ACROSS your report. If you have multiple hierarchies, then you would have to know how many possible combinations or nestings were going to result from your data -- so you could get the column names correct.
cynthia