ls command

[Anand Viswanathan]

Hello,
        I am not sure if you guys are the 
right people to contact still I am sending it.
        Sometimes the unix 'ls' command does not
display anything though I know there are
files in that directory. If I rename the files,
I am able to see them through 'ls' but when
I rename it back to original name, nothing
shows in 'ls'. I am using Solaris.
Any reason why this happens?

Thanks in advance,
Anand