OPC client

Hello,
In the meantime I did some more testing and some more strange behaivior.
As for now, this is the only way I can get it to work:
 
I read 1 float and one bool. If I read only the float, it works. When I add the bool, everything stops, but adding the bool the second time everything works back again.
But ... when trying to add a new float, bool, or whatever, everything stops working (also when trying to add them double). I does one read of the values for the first 2 items, the rest can't get their values.
In the OPC client, I see all the requests (callbacks) and it starts to puts out all its values, but they aren't received by Proview.

A second strange issue: when the OPC server quits, Proviewr seems to hang. When the server gets back up, no new values are fetched, probably because the callback is lost and never build up again.
I think the OPC client isn't production safe for the moment with this behaivior even if the value are informal. Is it usefull to put energy in the client or is this a path to leave?