From a dervived table standpoint this works for sure in 4.1.0 and 4.1.1.
SELECT * FROM Term, (SELECT CONCAT('%', subcategory, '%') as sub FROM SubCategory) subc WHERE term = sub
and Term.vol > 2500 and Term.price > 0.25
ORDER BY Term.price DESC
I would take the individual queries and run them by themselves and make sure they work fine. Actually after just looking at your query, I found the problem.
Your original query:
SELECT DISTINCT Cust_Billing_Info.Cust_ID FROM Cust_Billing_Info, Customers WHERE Cust_Billing_Info.Cust_ID = Customers.Cust_ID;
Your subquery:
SELECT DISTINCT Cust_ID FROM Cust_Billing_Info WHERE Cust_ID.Cust_Billing_Info IN ( SELECT Cust_ID FROM Customers);
The problem by look at it is that you have right after the where clause Cust_ID.Cust_Billing_Info, but based on the select Cust_ID is a field name and Cust_Billing_Info is a table name. So try the query like this.
SELECT DISTINCT Cust_ID FROM Cust_Billing_Info WHERE Cust_Billing_Info.Cust_ID IN ( SELECT Cust_ID FROM Customers);
You should be all setup now.
Donny