When I click "back" button selection screen is not appearing

Dear All,

1) I have a "report" which takes some parameteres in the seclection screen ( standard 1000 ) and displayes a report. This is transported. Say the name is ZPRG1

2) We have copied ZPRG1 to ZPRG_temp and modified some logic and copied back to ZPRG1.

3) All looks fine but in ZPRG1 in SE80 it is not displaying screen "1000" listed. And when I pressed "back" button from the standard report menu it is going into "blank" screen first. and then when i click again it comes to the selection screen. I understand that some thing happened with GUI stuff but ran out of all ideas and coming here to get some help from you..

I am almost in a lost state.. can you please suggest me?

Thanks for your time.

Regards,

Kiran