If both titles are showing on the first step, check that there is a RUN; between the REPORT step and the second title definition.
If you want the second title to replace the first, be sure to use TITLE1 not TITLE2.
Double check the ODS destinations to make sure that you are not mixing the destination and the file extension.
The following will show only the first title for the REPORT step and both for the PRINT.
[pre]ods html file="c:\temp\twotitl.html";
ods pdf file="c:\temp\twotitl.pdf";
title1 "report title";
Proc report data=sashelp.class nowd;
run;
title2 "print title";
proc print data =sashelp.class;
run;
ods _all_ close;