You're not very clear about where the error occurs. In Foxpro or a Foxpro Application or in your SSIS package.
As you've got the SSIS package to use shared access I assume it's rather not the SSIS package.
If Dan and JRB-Bldr hit the nail, the problem is not, that SSIS blocks other access, but that Foxpro or the Foxpro app requitres exclusive access. See? The problem can come from both sides, here SSIS surely is not the evil side blocking access. If a file is open shared you cannot access it exclusively.
Foxpros defaults are something I question, but having exclusive access is developer friendly of course, as a developer then can easily make table alterations on the fly. As Foxpro is the development environment it's main intent is to let the developer do his work, not the user.
You (or let's say I) typically have a rpoduction and a test- and development version of your databases and work with the developer version in Foxpro, in the test database in testing and in the production database with the final product.
Your usage of foxpro is rather an administrative usage. Do as dan suggests and the problem will go away.
Bye, Olaf.