curlftpfs segfaults when trying to modify files

The curlftpfs version 0.9.1-1+b1 (debian lenny/testing) successfully connects to the FTP server, lists the files correctly, but terminates with a segfault when trying to modify (e.g. delete) a file:

server:/mnt/ftpbackup# rm TMP.outpost.new
rm: remove regular empty file `TMP.outpost.new'? y
rm: cannot remove `TMP.outpost.new': Software caused connection abort

When running in verbose debug mode, the following output can be observed:

unique: 25, opcode: GETATTR (3), nodeid: 1, insize: 40
unique: 25, error: 0 (Success), outsize: 112
unique: 26, opcode: LOOKUP (1), nodeid: 1, insize: 56
LOOKUP /TMP.outpost.new
NODEID: 3
unique: 26, error: 0 (Success), outsize: 136
unique: 27, opcode: ACCESS (34), nodeid: 1, insize: 48
ACCESS / 01
unique: 27, error: -38 (Function not implemented), outsize: 16
unique: 28, opcode: LOOKUP (1), nodeid: 1, insize: 56
LOOKUP /TMP.outpost.new
NODEID: 3
unique: 28, error: 0 (Success), outsize: 136
unique: 29, opcode: UNLINK (10), nodeid: 1, insize: 56
UNLINK /TMP.outpost.new
* Couldn't find host server in the .netrc file, using defaults
* Re-using existing connection! (#0) with host server
* Connected to server (192.168.0.1) port 21 (#0)
> CWD /
< 250 Directory successfully changed.
> SIZE (nil)
< 550 Could not get file size.
> REST 0
< 350 Restart position accepted (0).
./mount_ftpbackup.sh: line 2: 2825 Segmentation fault curlftpfs -d -v -o ftp_port=- ftp://user:password@server /mnt/ftpbackup

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As you can see, we have already tried to avoid passive mode with no success - it has no effect on the issue.

Eagerly awaiting your response,
Sincerely
Daniel