Singleton Problems

I have an issue with singleton implementation in C#, my business object has a 3 hash tables this class follows a singleton pattern. I have the following test scenario.I have a test.aspx which populates the hash tables with the data from the database.I have an exe which also instantiates this class to view the refreshed data.I run the aspx first and then run the exe, when the exe is run it says the instance is already present and returns the instance but that instance doesnot have any data in the hash table. My issue is that the singleton is creating a fresh instance or cleaning the data in the hashtable everytime its called from a client could the C# experts throw some light on this.
Thanks