search for: unzreadcurrentfile

I'm doing some work in C with the R_ExternalPointer interface, and having some seg fault problems. I expect the crash is my fault, bad pointer in my code causing a fault later etc, but I'm curious about the point of failure. R almost always falls over in a call to unzReadCurrentFile following a burst of disk activity. I'm definitely not doing anything that would call that explicitly, and I don't notice the bursts of disk activity in similar work without using my package. Any idea what might be causing a compressed file read? Something to do with lazy loading, maybe?...