Problem:

As reported in Google Groups

http://groups.google.com/group/mongodb-user/browse_thread/thread/34cda5dac73edff7

Database names called

• buy
• buy_201107
• buy_201108

User did
> use buy
> db.dropdatabse()

From the logs it can be seen

Sat Jul 23 23:49:38 [conn663642] DROP DATABASE: buy
Sat Jul 23 23:49:38 [conn663642] DBConfig::dropDatabase: buy
Sat Jul 23 23:49:39 [conn663642] about to log metadata event: { _id:
"mg03-2011-07-23T15:49:38-0", server: "mg03", clientAddr: "N/A", time:
new Date(1311436179027), what: "dropDatabase.start", ns: "buy",
details: {} }

Look good, but next message it looks like the NS changed

Sat Jul 23 23:49:39 [conn663642] about to log metadata event: { _id:
"mg03-2011-07-23T15:49:39-1", server: "mg03", clientAddr: "N/A", time:
new Date(1311436179091), what: "dropCollection.start", ns:
"buy_201107.data", details: {} }

This message comes from chunk.cpp:775, however, the code path to here looks reasombale.