Best way to manage Listview items from Indy 10 thread

Best way to manage Listview items from Indy 10 thread

I'm making a multi user remote administration tool, a sort of VNC but
which support multi remote desktop viewer a bit like Teamviewer does.
I have a Delphi Form which only contains a TListview, this listview
contains users list which are currently connected to the server.
When a connection is dropped, the listview item is deleted.
For some reason I got some random problems while deleting more than a
single item, for example if I decide to flush the whole server
connections, if I have more than 1 listview item, it start going crazy.
Sometimes no error show up, just some items remain listed, sometimes it
shows "address violations errors".
As I was before using pure Winsock API to make Client / Server
application, I maybe use badly Indy components.
A short explanation about my way of managing the Server component.
My application is Multi Server, which means user could create one or many
servers at the same time. When a new Server is created by the user it run
a new thread which will create a new indy Server component and setup
needed events (OnConnect, OnExecute, OnDisconnect) etc...
Every commands that acts with some VCL form are of course Synchronize
using the Synchronize(); delphi method.
When a new connection show up, i create from the Server Execute method a
new listview item, then i set the new listview item to the AContext.data
property.
When a connection is dropped on the OnDisconnect event, I delete the
listview item then empty the AContext data to be sure, he wont do it again
when he will be automatically destroy.
Synchronize(procedure begin
TListItem(AContext.data).Delete;
end);
AContext.data := nil;
This way of doing works very badly when I have more than a single
connection. After debugging it seems even with the Synchronize commands
are executed at the same time which could result conflicts in the VCL
form.
I'm not an expert in Indy10, any advice would be surely appreciate.
Thank you in advance and sorry for my poor english.