Dont ever ress nocopy items until linden fix their servers.
As best i can determine due to recent code changes th is is what happens.
1. you ress a nocopy item. the item is due to being nocopy removed from inventory.
2. lag or other issues causes a cannot ress problem. the processing of the ress attempt is aborted with a cannot ress due to blah reason
3. item if being nocopy is supposed to be placed back in inventory. but that has been lindened. so it dont happen.
Result: if there are any processing errors ressing a nocopy item its now lost forever
Conclusion: dont buy or use nocopy items
Demonstration:
Change your active group to one that cannot ress items on your land. Try place a nocopy item on your own land.
Watch the item poof