ASP content disposition over SSL

[ChenChen]

I have a problem with content-disposition changing.

Until recently, while we used to work with http, using
Response.AddHeader " content-disposition" ," attachment;
filename=report.xls"
Worked fine, excel spreadsheets were exported with no problem.

Moving the IIS to work with SSL, has some affect on the result and the excel
doesn't build.

Suggestions?