beta 2.01 snapshot does not recognize ${ThreadIndex}

Hello,
I have a testcase in which the first teststep is a file datasource. My file location looks like C:\TVObjectsFiles\TVObject${ThreadIndex}.txt

When I run just the teststep, I am able to see the rows. However when I run the testcase, the teststep fails with the following error.

java.io.FileNotFoundException: C:\TVObjectsFiles\TVObject.txt (The system cannot find the file specified)

I am using the snapshot release along with jar files you had sent me on 11/22/07

Thanks

Ali