Dsn is working but odbc_execute hangs in php

I have a problem in my ubuntu and debian 5 system
my database is mssql2000 on windows 2003 server
in both linux servers DSN is correct and isql works(query result up to 1.5GB saved to file)
in my php program i can connect to mssql without any problem(trying wrong password causes odbc error so dsn is working)
but when i try "odbc_execute" any sql query it hangs !!!
i don't know what is the problem and what do i have to do!

Just to make sure I understand your situation.

You have been able to connect to a mssql server using the mssql extension. But when you try to connect using the odbc extension your SQL queries are not executing when you use odbc_execute.

1) is odbc installed and configured correctly
2) are you using the same DSN from the mssql extension?
3) are you able to connect and get a valid resource back?
4) did you create the prepared statement with no problems?
5) what errors, if any, are you getting back?
6) how long are you letting it run before you decided it was "hung"?
7) where is the code to review?

http://catb.org/~esr/faqs/smart-questions.html

the dsn is ok and is working very fast in isql comman in linux
but not working in php, odbc_exec hangs (i waits for more than 30 mins) no error no timeout ,no cpu usage,no network usage
my code is just very simple