Hi (first of all, thanks for your attention & sorry for my bad english hahaha also this is not a programming error, or thats what I think, I think this is an error in some configuration of the server or something else but I dont know what)

I have a php script (is running like a process of linux, its not running on the web browser) that send SMS via SMPP on the port 2055 (using sockets in php) & then inserts like 10,000 rows into a dababase on MySQL, the script gets the data from a XML file; firts it was running in a shared server (Hostgator is our hosting provider) & at the begining it worked fine, with no trouble, but 5 months later an error appear, the process just die with no reason, the script only sent & inserted 700 rows in the table of the database & the process didnt show any warning or error, nothing appears in the error logs, & I didnt make any change in the script Hostgator never helped us hahaha so we decided to move the script from the shared server to a dedicated server; I thought it was a memory problem or something like that, but when we move the script to the dedicated server the problem just get worse, the script die when has just sent & inserted 40 to 50 rows to the database

the information about this error:

1. the shared server is on Red Hat 4.1.2-46 & the dedicated server is on CentOS 5.4
2. I have commented the line that sends the SMS, & the problem remains
3. in the shared server, at the begining the script was fine, but then the script started to die when has just inserted 700 aprox. in the database, & now the script is dying when has inserted 2500 rows, its better but we didnt change anything
4. in the dedicated server, the script dies when has just inserted like 40 row in the table
5. the script, before it dies, change to a zombie process & we dont know why
6. the usage of memory appears to be 0.3%, and of the cpu appears to be 0.7% to 1%
7. I have changed the max memory limit of php to 128Mb, and even to -1 (so php wont have any limit) but the problem remains
8. we have the limit of 50 connections of mysql at the same time, so I think this is not the problem
9. Im using mysqli to connect from php to mysql
   1. Hostgator report that they haven't made any change or update in the servers

what could be the problem?? what should I do??? what should I search??? is something in the logic Im missing?? what steps do I have to follow when managing & searching problems of process on Linux???

thank you very much, I think this is not a programming problem, but you have more experience than me, you can tell me thanks!!! bye!!! :)