Thanks, Mark. That worked.

And I found the problem with the error messages. They're not from the build process, but from when the data coming in isn't a full string, so it fails when I try to chop it up, and the Immidiate window isn't clearing for each time I run the program...

Now, for the timers, I put in a 'Console.write' line in the check routine, writing the interval and whether Enabled is true or false, and they're getting set. Could the problem be that since the Check routine is called from the 'data-received-from-serialport' routine, which is running in a different thread and the timers should be running in the GUI thread, be why they aren't firing?

Stig