Could not find prepared statement with handle 1.

[Macromedia][SQLServer JDBC Driver][SQLServer]Could not find prepared statement with handle 1.

I'm getting this error message in what appear to be random ways. The first time I look at a page I might not get it, but the second time I might. I discovered that removing a cfqueryparam tag worked, but that is not really a safe solution. I checked that the cf_sql_type matched the database field, and in one case changed a cf_sql_varchar to a cf_sql_char so it would match a SQL Server nchar(10) field. But still these errors. Any ideas? I've not had any luck Googling this.

I should add that I'm running Coldfusion 9 as a Tomcat webapp on a Linux server. The database is SQL Server 2005, I think.