[Lazarus] PageControl tabs not showing

[Werner Pamler]

Thanks Luiz. Unfortunately, after I removed "Loaded" and added a new 
method "InitializeWnd" containing the "NewWorksheet" call there is no 
improvement. Your answer, however, guided me to the "Setup" method in 
which the column and rows are prepared. At its beginning I added an "if 
csLoading in ComponentState then exit" - and now the issue is gone even 
with the old "Loaded" in place.