Printing from Print preview for the Purchase order in ME23N ,Print Icon is greyed out.

We have an issue, We where able to print from the Print Preview Screen for the Purchase order in ME23N transaction earlier few months back, now we are not able to do that now?. I have checked the User Profile Paramenters, Output Conditions and SAP GUI wiht help of ABAP. Please help me out to activate the Print Icon in the Print Preview for the Purchase order in ME23N Transaction. Pls let me know how to activate?

Regards

Anil