Connection string problems

I seem to have a problem forming a suitable connect string for the PostgreSQL ODBC
driver. I am using Windows XP and visual studio.net 2003 with C#.

If I have a connection string as:

string strConnect = "DSN=PostgreSQL30;UID=postgres;SERVER=192.168.1.102;
Port=5432;";

And I have defined the database to connec to in the DSN then everything works fine.
What I want to do however is not have to define a DSN for every database that I have or
when new ones are created. Normally (with MS SQLServer etc.) I would specify the
driver name and database in the connection string itself. So I use:

string strConnect = "DRIVER={PostgreSQL};UID=postgres;SERVER=192.168.1.102;
Port=5432; Database=webroster";

I get an exception (OdbcException) thrown in C# that has NO error information at all in it
and the connection fails.

I get this same problem if I specify the DSN but the DSN definition itself does not specify
a database. Am I using the right keywords in the connection string? I have tried to look
around for definitions of the keywords that the ODBC driver accepts, but I can only find
various examples like the one I am using.

If I specify a DSN in the connect string and the DSN specifies a database then the
connection and all other functions work just fine. Any ODBC exceptions thrown at any
other point in my code have all the correct error information in them.

Any suggestions appreciated.

Thanks
Gary.