Oracle Database Discussions

Hi.

Now I'm using oracle 9i on windows 2003 server.
I have a lot of packages and procedures and they run to conduct transaction job.

Few days ago I found some bugs in this packages and fixed completely.
But after fixing bugs, I couldn't compile some packages.
There are 2 packages that I faced problem.
A and B.
B is just a package. A is package that call B with parameters.

When I tried to compile those 2 packages, I see error MSG 'ORA-04021 timeout occurred while waiting to lock object'.
But another packages or procedure doesn't have problem at all.
I tried to restart server several times. But it couldn't be fixed.

I googled to solve this problem. someone said that it could have invalid code.
But once I compiled to see that what's going on.
It takes so long time.

Basically what things should I check and what's the main reason of this error?

Thanks in advance.
Dan