I've been running 2.1.6 in Production with the patch from Bug 17, for a month, and everything has been working fine. As a reminder, this patch corrects a bug in MS-CHAP with the calculation of the MS-CHAPv1 challenge passed to ntlm_auth. It causes inappropriate Logon Failure errors, in certain circumstances having to do with the case of the userid and the logon method (see the bug report and previous posts for more details if you didn't follow the thread). Others have reported this problem in the past and the workaround has been to create all users in a specific case and force the userid to the same case in FR. (I'd really like to see this fix incorporated in the code, as other RADIUS servers don't have this userid case-sensitivity issue and this gives people an opportunity to cast stones at FR.) Arran: You seemed a bit interested in this patch - have you had the time/desire to apply and test it? If anyone else has some time to apply and test the patch, it is very much appreciated. Thanks in advance for your assistance and feedback..