I have a main DTS package (call this "Package A") that calls another
DTS package (call this "Package B"). Package "B" does many things but
one of the last steps it uses SP_RENAME to rename some tables. Package
"B" runs just fine on its own. However, when called from Package "A",
Package "A" returns an error. The details of this error shows:

"Changing any part of an object name could break scripts and stored
procedures"

This is the warning message that always pops up when you use this
sproc. When I run Package "B" directly, I get no such message. Only
when run from package "A"

Never mind, I figured it out. Package B had its workflow properties
set to "Run under main thread". When I unchecked that, the warnings
didn't trigger an error in the calling package