OK, so the other thing in common is that both tablets are only opening shared versions from my desktop. I check the share properties on my desktop and found each notebook to have 2-3 "? Unknown Contact Read/Write" and the homegroup share gone. So once I deleted the unknown contact, and then re-added the homegroup share to read/write, all the inking started working again on the shares. The problem with homegroup is that my desktop keeps losing the TPC's on the network. Those TPC's however can see and use the shares completely.