MySQL ODBS DNS global.asa not working correctly

Hi, i am moving websites from one server to another and they all use the mysql 3.51 odbc driver. the server ti is from is 2003 x86, the destination is 2008 R2 Ent x64

i am having difficulty with one website that says:

80004005|[Microsoft][ODBC_Driver_Manager]_Data_source_name_not_found_and_no_default_driver_specified

the dsn string i am using (which only differs by the DB, user, passsword to other websites:

Session("DSN") = "DRIVER={MySQL ODBC 3.51 Driver};Server=10.5.74.4;Port=3309;Database=<db>;Uid=<user>;Pwd=<password>"

i have verified that the credentials i am using work by using the ODBC manager and also sqlyog.

so i know the credentials work and the driver specified is all ok as other websites are using it without any issue.

i have the 3.51 driver installed for both 32 and 64 bit operation (both show up correctly in the 32 and 64 bit odbc managers. (in fact i have both 3.51 and 5.1 versions of the mysql odbc connector installed for both 32bit and 64bit but changing the driver in the global.asa file does not work.)