strange problem: can't start many program for certain user

[zhu blue]

Hi,
I installed F7 on my HP laptop(nc6400),I found strange problems:

for first User A, I choose to change desktop setting(language,etc), but
it just can't start the prompt window to ask root password.

I login as "root", it can start the "system-config-language" program.
I create another user B, login as  User B under X,it also works.

what happened to this user account? it seems some setting is not
correct.

BTW, I downloaded "jre-6u1-linux-i586.bin" from "java.com",followed the
instruction, but it doesn't work. even not for "root".

AND I installed F7 on my desktop, no above such problems.

Thanks a lot!

Paul