Sync_and_start_rx_streaming_at

Hi All,
I have an issue with the pps syncing on the USRP2. If I call
sync_and_start_rx_streaming_at(0,0,0) then the function call will
complete
about 1 out of 15 tries (so it just hangs in that call most of the
time).
I’ve

looked at my pps signal going into the USRP2 and it is exactly what is
required. When the call does run to completion and data starts
streaming it
looks like the timestamp counter is being set properly (i.e. set to 1)
. Has
anyone run into this problem? I’ve experienced this on multiple
USRP2s.

Thanks,
David