[RESOLVED] "Can't open Clipboard" message, what to do ?

I need grab the data from the scrolling window in another application. The data have a table structure, so I can get them manually using Ctrl-C,Ctrl-V method and stepping down row-by-row.
I am trying to create a simple program in VB6 which could do it automatically. I imitated all keyboard keys and it works. However, I must introduce some time delays at each step like "Sleep 400" or I get "Can't open Clipboard" message". However, if the number of rows 200 or so it is slow. I read somewhere to try the following to avoid "Sleep" command:

Get ProcID of the process and insert WaitForInputIdle ProcID.

I did that at each step of the cycle for the process where the window belongs to and for the clipboard process like

hwnd1 = GetClipboardOwner()
GetWindowThreadProcessId hwnd, procid
GetWindowThreadProcessId hwnd1, procid1
WaitForInputIdle procid, INFINITE
WaitForInputIdle procid1, INFINITE

Here hwnd is the handle to the scrolling window. It is not working. I am getting occasionally that message "Can't open Clipboard". I tried to introduce Error handling trying to repeat Ctrl-C,Ctrl-V sequence few times, but the program locks in such loop of error corrections.

Could anyone advise me how to handle this "Can't open Clipboard" problem ?

After few days I found a solution of this problem in one forum ...

I removed all WaitForInputIdle, they don't work. A partial solution is to put
DoEvents before accessing Clipboard. Then you get Error 521 "Can't open Clipboard" very rarely. When I added it twice like

On Error Resume Next
...
DoEvents
Clip$=Clipboard.GetText
Sleep 10
DoEvents
Clip$=Clipboard.GetText
...
it completely resolved the problem.
Hope that it will be useful for someone.