Can't change subnet mask

[cwachs]

Running a number of switches with the same problem - we are unable to change our subnet mask. We were 255.255.255.0 on our management LAN but have moved to 255.255.248.0. The switches are keeping the same IP but changing the subnet mask. When I change it in the config page and hit save, it looks like it saved it but next time I log in, it's back to 255.255.255.0 I've gone through this a number of times and it won't seem to stick.

Happens with 1.4.7 and 1.4.8rc3 (multiple devices on each firmware).

[cwachs]

If I change BOTH the IP address and the subnet mask, it sticks. To get around this, I change both then change the IP back to where I want it.