I can tell you this:
I´m working with vfp 6.0 and I´m building an app wich have some compound indexes. I used the RI builder and it warns that these indexes *might* not function as expected.
Through the preliminary test, it seems to be working fine; but I will check it out to see if further problems appear.
Also check thread # 248243 dated jul 30/99 to know about a bug I discovered in the RI builder.

>>I once read that theyre was a bug in the referential integrity builder in VFP 3.0 (which I am using right now). The bug was supposedly caused by RI compound indexes.
>>
>>Is it true ?
>>
>>In the coming weeks I will be beginning to work with VFP 6 (with SP3). What does it look like with the RI builder in that version ?
>
>I don't use compound primary indexes, so I can't tell you from experience, but I can repeat what I've read over and over: the RI builder does NOT work with compound primary indexes.