Freeradius process crash receiving answers from Microsoft NPS Server

[IT Support]

Good afternoon

I'm a newbie with freeradius and I'm trying to configure a radius
proxy server that makes to a server microsoft radius nps.

I have a Enterasys C3 switch that sends auth requests to my
Freeradius. If the request is for auth a MAC the FR auth locally, but
if  the request is for auth a windows user (EAP) the FR resend the
request to the Microsoft NPS radius server.

I use Debian 6.0 and the debian package of FR (version is 2.1.10).

The problem is that when the Microsoft RADIUS server returns an accept
packet, the freeradius server process dies. But if the answer is
reject, the process works properly.

When the process dies, only appears in the syslog the following line:

"November 11 16:20:35 debian-radius kernel: [2380.591594] freeradius
[1749]: segfault at 3934c708 b76fd497 ip sp error 4 in libfreeradius
b5ae4970-radius-2.1.10.so
[+1 b76ec000 E000]"

Can anyone help me?

Sorry for my poor English.

Best greetings

Toni