Checking for a window tab in a filter function

[Gintaras]

With some windows, accessible object functions (AOF) don't work in filter-functions. I don't know why. For example with .NET forms.
In some windows AOF don't work for some short time after the window is created. However in filter-functions we cannot wait.
Also can depend on whether using low-level trigger hook (look in Options).
Alternatively use control functions or messages, or "find image".