I can find no evidence of that - but it's something that can easily be settled. If the LIB and INCLUDE environment variables are cleared (
I've been running Strawberry with those variables unset for over a year (during which time I've installed numerous extensions) without any problems at all.
I've also tried adding to the search paths via the LIB and INCLUDE variables, but any aditional paths that are included in those variables are simply ignored. Afaict neither Strawberry Perl nor the MinGW installation that ships with it take any notice whatsoever of LIB and INCLUDE.