I had a similar issue (on OpenSUSE 10.3 but different error message) and then found this link.

(try it later it seems the iptel.org site is temporarily down)

http://www.iptel.org/faq/why_does_my_mysql_5_0_x_connection_time_out_when_using_ser_0_9_x

There is a MySQL connection timeout issue. I would see the connection go away and not reconnect if SER 0.9.7 was idle overnight running MySQL 5.0.45. Originally I fixed it by cranking up the connection timeout settings in MySQL but that is not the best way to fix it. SER 2.0 claims this issue is corrected but I’m not doing SER 2.0 yet.

John

From: serusers-bounces@lists.iptel.org [mailto:serusers-bounces@lists.iptel.org] On Behalf Of muhammad akl
Sent: Sunday, June 15, 2008 1:27 AM
To: serusers@lists.iptel.org
Subject: [Serusers] xlite registration error 500 : Server Internal error

hey all ,

my problem is a bit strange . i have succeeded in compiling ser 0.9.7 on solaris 10 x86 arch and the compilation process went smoothly without any troubles ( i mean the last time i compiled ser ) after that i have configured Ser to work with MySQL 5 and aslo there werent any problems happened

the problem is :

i have added some users in the subscriber table to check that ser is preconfigured correctly using x-lite softphone and also there weren't any problems for the first time i registered with xlite , the problem appears when i unregistered the account and leave SER running for several hours without any user'registration ( about 10 hrs SER is idle or more )

So my question is :

is there any pre-determined period that ser shouldnt be idle ? or it there any configuration responsible for determining the max time that SER can  rest in idle status ?

the error message that appears in the x-lite winow is " Registration error 500 : Server internal Error "

Note : when i do restarting SER all things are fine and i can be able to registration without any error , the error appear when i do unregistration and SER is idle

thanks in advance