Table not dropped correctly in SQL Server Express 2008
Whether using dbo or not, always specify the schema prefix explicitly. Otherwise, if you have users with different default schemas, you could end up with objects in a schema you didn't expect. One user creates a table in one schema, and the other can't see it. Here is a quick example:

CREATE SCHEMA floob AUTHORIZATION dbo;
GO

CREATE USER blat1 
  WITHOUT LOGIN WITH DEFAULT_SCHEMA = floob;

CREATE USER blat2 
  WITHOUT LOGIN WITH DEFAULT_SCHEMA = dbo;

GRANT CREATE TABLE TO blat1, blat2;
GRANT ALTER ON SCHEMA::floob TO blat1, blat2;
GRANT ALTER ON SCHEMA::dbo TO blat1, blat2;

EXECUTE AS USER = 'blat1';
GO
CREATE TABLE Employees(ID INT);
GO
REVERT;

SELECT s.name, t.name
FROM sys.tables AS t
INNER JOIN sys.schemas AS s
ON t.[schema_id] = s.[schema_id]
WHERE t.name = N'Employees';

EXECUTE AS USER = 'blat2';
GO
CREATE TABLE Employees(ID INT);
GO
REVERT;

SELECT s.name, t.name
FROM sys.tables AS t
INNER JOIN sys.schemas AS s
ON t.[schema_id] = s.[schema_id]
WHERE t.name = N'Employees';


Results:

-----  ---------
floob  Employees

-----  ---------
dbo    Employees
floob  Employees