trouble transferring flight log from FLARM to Tophat

I use a portable PowerFLARM connected via serial (RS232) cable to a Nook running Tophat (which is based on XCsoar). This setup works nicely, the FLARM is the GPS source for the Nook, and I can see FLARM traffic on the Nook's display, and can send task declarations from the Nook into the FLARM. After a flight Tophat asks whether I want to import the flight log from the FLARM. I must first tell the FLARM to do the "IGC readout" step to copy the log into its memory card, and only then tell the Nook to go ahead and look for logs on the FLARM. Select the latest file, and it transfers, slowly through the serial cable, during the while the FLARM says it is in "maintenance mode". That has worked OK many times. That way I leave the FLARM with its memory card in the glider, and only take the Nook home with the flight logs in its memory card. Tophat builds its own log file too, but the one from the FLARM is IGC-security-approved.

But Yesterday when I tried to copy the flight log file into the Nook it proceeded some 90% of the way through the transfer, then the Nook said the transfer failed. Tried it several times to no avail. Tried transferring an older flight log and that worked OK. But not the file I wanted.

What could be causing this problem? This flight was 5 hours long. Is there a timeout built into the FLARM's maintenance mode? Or Tophat's transfer? Is the data corrupted in the FLARM's memory card? (Alas I left that card in the glider when I went home.)

My FLARM config file says "$PFLAC,S,BAUD,2", i.e., 19200 baud, would it be safe to use 38400, say, to speed the transfers up?

Did the storage capacity in the Nook fill up?
Or is it unlimited storage and new IGC files erase the old ones to make room.
Maybe when you downloaded that old file it just re-wrote it and didn't take up any more space?

On Saturday, June 20, 2020 at 11:33:56 AM UTC-4, Nick Kennedy wrote:
Did the storage capacity in the Nook fill up?
Or is it unlimited storage and new IGC files erase the old ones to make room.
Maybe when you downloaded that old file it just re-wrote it and didn't take up any more space?

There is almost a gigabyte of free space in the Nook's SD card. And even more in the FLARM.

One thing I learned from the test transfer of an older file: Tophat on the Nook (presumably) names the file with today's date rather than the flight date as I expected. E.g., the file 2020-06-14-FLA-7LW-01.igc re-transferred on June 19 as another file named 2020-06-19-FLA-7LW-01.igc with identical contents. I wish I'd brought the FLARM SD card home to check what files are on it.

Flew again today. Log file transferred to Nook with no problems. Last week's log file still would not complete transfer. Took FLARM's SD card home, found all the files on it, and the one that wouldn't transfer seems fine. That file is larger than the other recent ones, but an even larger one transferred OK last year. Could the issue be caused by the FLARM firmware update (version 6.83) that I did this year?