The SP2 has not been released yet. What you have is CTP of SP2 (pre-beta).
For the list of fixes see http://download.microsoft.com/download/a/b/3/ab3fd0de-74e9-4b0e-9510-82e9bd3a49e4/VFP9SP2_OctCTP_FixList.htm. The relevant one says, VFP allows to create structural CDX for a table opened in shared mode, which may cause header corruption.

>Does anyone has any answer to this.
>
>I have the following code:
>

>Use table1 shared
>Index on field1 tag tfl
>

>This works with VFP9 SP1
>
>BUT... when I try the same code when SP2 has been installed, I get an error for the index line: "File must be opened exclusively."
>
>This code works with SP2:
>

>Use table1 excl
>Index on field1 tag tfl
>

>The only differens in the enviroment is that SP2 has been installed in the second case.