It isn't doing anything odd or strange. It is doing exactly what it is documented to do, which is to return a null-terminated string in the buffer you have provided. VB doesn't understand null-terminated strings (in the sense that it doesn't know that CHR(0) is a string terminator), so when you display the string it actually displays the entire original buffer, which is your original string overwritten at the beginning by the stripped filename plus a CHR(0)

So you need to extract

Left$(strResult, instr(strResult, Chr$(0))-1)

or

Split(strResult,Chr$(0))(0)

Thanks much Strongm.  Yes indeed that return is null terminated.  The API documentation was a bit ambiguous about the results and they weren't what I expected.

Since I am only looping through a few dozen paths at the most, speed isn't an issue.  But I will have to see whether it is more efficient to just use VB string functions or the API call or alternatively pass a fixed length string.  The fixed length string gets a cleaner result, but the tail of the string still must be clipped.

Again, I appreciate your feedback.
Cheers, Bill