I am trying to connect using ASP.NET.  I set up all the permission on all the DCOM servers.  If the optimizer is turned on, then my connection just hangs.  Once I turn off the optimizer, i can connect and query the data with no problem.

I then have to insert checks.  I insert into CheckExpenseLine first and then into Check.  According to examples I have seen here I am setting FQSaveToCache equal to 1 during the insert.  WHen I do this I am getting an error back: System.Runtime.InteropServices.COMException: [QODBC] Optimizer is turned off

If I omit FQSaveToCache or I set it equal to 0 it just hangs

ASP.NET runs queries as multiple treads, and the QODBC optimizer is single user only. So you need to setup a different optimizer file for the ASP.NET application to use than the other disktop applications. To do this, set up a seperate System DSN (see: How do I create or configure a QODBC DSN? ) and specify a fixed location of the optimizer database folder for the ASP.NET application to use (like: C:\Program Files\QODBC Driver for QuickBooks) instead of the default %UserProfile% method. Finally the user or system account used (Anonymous web user IUSR_machinename, ASPNET user and INTERACTIVE) by the ASP.NET application must all have full rights to the optimizer folder.

See also: ASP.NET vs Classic ASP 

when I turn the optimizer back on my app hangs when trying to open the connection.  But when I use the DisplaySql.asp page it works fine.  I saw the thread about ASP.NET and classic ASP and I put the AspCompat="True"  in the page directive, but it made no difference.

I don't mind not using the optimizer.  Shouldn't I be able to do the inserts with the optimizer turned off and not get the error:  Optimizer is turned off?

That did it thanks.

I was under the assumption that once I turned off the optimizer it ignored all other setting on that page since they become disabled.

Now I want to turn on the optimizer. 

I created a seperate DSN and optimizer folder for my ASP app. 

which users do I have to give permissions to the folder so that my connection won't hang?  Currently it only doesn't hang if I turn off the optimizer.