proxy confusion

In my pc, there are many place where the proxy is set. but which will
make a role to my target working task is not very clear.

Today, I set the svn proxy through the perl script. then I tried to
update the code through svn and I think the proxy will works. After I
failed for several times to download the external resource. I check
the run-script to find that there is the a properties file which
contain the local proxy setting. and It seems that this setting have
the high priority than others.

The same things occurs in the cvs proxy setting in the eclipse.
luckily, I got the way to fight out.