Window Subfile Problem

Hello
I wrote a RPG program that handles two Window Subfile. If user  puts '5' for a 
subfile record in Window-1, the program will display the Window-subfile-2 with 
the details of the selected record. Now if user puts anything other than '5' in 
Window-subfile-1, the program reverse images that and gives error message. When 
the Window-subfile-2 apperas on the screen, user can still see the option '5' 
he entered in the first window, because that portion of the window-subfile-1 is 
not being covered by window-subfile-2.

Now I am having 2 problems. This is is what is happening:
1st Problem:
For the first time when Window-subfile-2 appears, window-subfile-1 disappears. 
But after the first time, Window-subfile-1 does not disappear when 
Window-subfile-2 appears. Why is it disappearing at the first time?

2nd Problem:
1. I put '4' in option field in the Window-subfile-1. Presses ENTER.
2. The program reverse-imaged that field.
3. I cleared that with field-exit, pressed ENTER.
4. No reverse-image any more.
5. I put '5' in the option field (does not matter whether I put for the same 
record or not), pressed ENTER.
6. The program displays the Window-subfile-2, but in the back of that, '4' 
reappeared on the same option field (where I entered '4' before) in the 
Window-subfile-1.
How is the '4' coming back? Is it in somewhere in buffer? How can I clear that? 
If the '4' is still there somewhere, why is the program not reading it by READC 
operation? While doing READC, the program is getting ' ' (blank) in the option 
field where I entered '4' before. But later '4' is reappearing. Why?

TIA
Amitava