Its seems random as to when a received email will indicate it has an attachment.
If you select "Folder/Message Default Format", it is set to "Use Global Setting" (as per Folder Properties, i have no idea what that really means but assume it means use whatever is set in Kmail Settings). Mine is set in the Kmail Settings, i presume, to prefer "plain text to html" because its the opposite of the setting to "prefer html to plain" which i assume if the global setting.
When i change this menu setting to "prefer plain.." or "prefer html.." the attachment indication below the heading information in the viewing pane appears and i can access the attachment.
I am guessing hugely here that because i've not selected "prefer html" in the kmail settings, the variable being used to hold this setting is not being set to "prefer plain" and the reason it randomly works depends whats in the uninitialised variable
This seems to be working again. Thanks for fixing