Hi,
I am not a Telerik guy but I have found a few workarounds for the postback\tabstrip which might help...
With the tabstrip, I tend to use onclienttabselected and onclienttabselecting to capture save\load events - then either physically save the data or store an it as XML in a asp:hidden field. I find that this allows me more granular control of the tab loading process which works in several scenarios.
Example saving content displayed in iframe (subform implements 'update' js method):
Anyway this is how I do it, but obviously this is influenced by project requirements and interface behaviour.