Windows Live Mail

I'm running WLM under Windows 7 64-bit. I use custom storage folders with a primary header folder then dated sub folders. Today I transferred highlighted emails from my input folder to one of the dated sub folders. I found that all the transferred messages were exactly the same. There was also an identical message in the Primary header folder but when I deleted it all the messages in the sub folders, when I tried to open them, resulted in a 'Cannot be Found' message. I've tried the WLM repair function via the Control Panel but the result is still the same. I've not has this problem when I transfer single emails from the input folder to Storage but only when I select a group of emails & try to transfer them to a Storage folder.