It's too early to tell if the TCL changes introduced in the the experimental tagged v6.7.0 have solved the problems but it didn't break existing script functionality so we're back to beta status now for these new features.
This release fixes a couple of bugs, provides some error reporting for VFS file parsing, and introduces default user options per group which can be really handy!
Site permission checking changed to default to access denied instead of granted. If you have added your own script commands make sure you add permissions flags for your commands. I believe the most common scripts already provide this for their features, but if you start getting "access denied" errors for things that worked before the upgrade check your permission settings.
Latest Version:
ioFTPD-v6.8.2.zip