I wrote the following little sample, and ran it at both v9.1.3 and v9.2, and it produced a pdf containing both the "proc report" and the "proc gplot" in both versions of SAS:
%let name=pdf002;
ods listing close;
ods pdf file="&name..pdf" notoc;
title "Proc Report";
proc report data=sashelp.class;
run;
title "Followed by Proc Gplot";
proc gplot data=sashelp.class;
plot height*age=sex;
run;
ods pdf close;
ods listing;
Does the above code work ok for you?
If the above code works ok for you, can you post up some example code that triggers the problem you're seeing?