Cannot enter SMTP username and password


In URLguard 0.41, I cannot seem to enter an SMTP username or password no matter what I try; the boxes are always greyed out.
For "Send email", checking the box does not enable the controls below as one would expect, but checking the box, hitting Apply, and returning to the Configuration window shows that the controls have been enabled.
The same does not go for "Authenticate to SMTP server". Checking that similarly doesn't enable the textboxes, but neither does hitting Apply and returning; I cannot seem to enable the boxes no matter what.