Weird ABAP debugger behavior

Experts,

I announcement a weird behaviour successful ABAP debugger. I person customized program. I americium trying to alteration the worth for a peculiar file successful an interior array successful debugger's edit mode. Itab has 42 records. I americium changing 1 file worth successful the 1st record. I tried doing this successful 2 ways: 

1) I selected the full row. Click tools->Change selected rows and past I alteration the worth for that compartment from 2000 to 150. 

2) I straight treble click the compartment that I privation to edit and change the worth for that compartment from 2000 to 150. 

In some cases, I spot that the compartment worth does not alteration to 150 successful the 1st attempt. Weirdly, alternatively of changing the compartment worth for the 1st record, it changes the compartment worth for that nonstop file successful the 42nd record. Now I again effort to edit the compartment worth for the 1st grounds the 2nd time.. Now, it allows maine to alteration the worth to 150. 

Observations: 

1) I spot that this contented happens lone with this interior array successful the customized program. I chose a antithetic itab and I played with the values. Its changing the intended compartment worth the precise archetypal time. 

2) I tried the aforesaid steps successful Eclipse alternatively of GUI and the aforesaid happens

3) I chose the 42nd enactment successful itab. Deleted it and past I tried to alteration the compartment worth successful 1st row. This clip around, it correctly changes the compartment worth lone for the 1st enactment successful the precise archetypal attempt. 

4) I thought this mightiness beryllium related to the information benignant of the cell. I spot that its Type P decimals 3. So alternatively of entering the worth arsenic 150, I tried to participate arsenic 150.000. As usual, archetypal effort does not enactment and it changes the worth lone successful the 2nd attempt. Also arsenic mentioned above, debugger changes the worth for the 42nd grounds alternatively of the 1st grounds successful the 1st attempt. 

As a tentative workaround, I person asked the users to participate the worth arsenic immoderate alphabet successful the cell. Say the idiosyncratic enters arsenic "A". Now the debugger gives an mistake successful taskbar

Change of adaptable LT_FINAL[1]-TOTAL rejected: New worth is invalid

Message no. TPDA052

After this error, idiosyncratic enters the worth arsenic 150. This way, it does not alteration the worth incorrectly successful the 42nd record. Clearly users are not blessed with this other step.

Can you delight fto maine cognize however this tin beryllium fixed.

Thanks

Bharath