I got one of these yesterday, thanks for the hard work Fry, will have a look on Monday for this one.
I think that message only happens during garbage collection and usually has to do with some native c function thinking it has a copy of a string that it can retain (usually from a bytr ptr) rather than a string it must forget about when it returns at the end of the function (from a $z parameter).
The problem locating these problem functions is that the function at fault may have been called many instructions in the past and only when garbage collection occurs (insert mysterious 13 rumour here) does the problem / warning appear.
I think that message only happens during garbage collection and usually has to do with some native c function thinking it has a copy of a string that it can retain (usually from a bytr ptr) rather than a string it must forget about when it returns at the end of the function (from a $z parameter).
The problem locating these problem functions is that the function at fault may have been called many instructions in the past and only when garbage collection occurs (insert mysterious 13 rumour here) does the problem / warning appear.