Autofs + sshfs fails to mount after upgrade to Natty

I recently upgraded from Maverick to Natty and my SSHFS automount map stopped working. I can manually mount servers using both sshfs and mount (with fstype fuse), but automount seems not even to register that a request for a particular location has been made. In addition, an attempt to use a USB stick on sdd to debug the issue results in the same behavior - namely no activity registered. It is as if the communication between kernel and autofs was broken.

Here is the output of sudo automount -fvdm:

autofs dump map information
===========================

global options: none configured

Mount point: /net

source(s):

  type: file
  map: /etc/auto.static

  www | -fstype=fuse,allow_other,reconnect,uid=1000,gid=1000 :sshfs\#user@www:/

Output of sudo automount -fdv:

Starting automounter version 5.0.5, master map /etc/auto.master.static
using kernel protocol version 5.02
lookup_nss_read_master: reading master file /etc/auto.master.static
parse_init: parse(sun): init gathered global options: (null)
lookup_read_master: lookup(file): read entry /net
master_do_mount: mounting /net
automount_path_to_fifo: fifo name /var/run/autofs.fifo-net
lookup_nss_read_map: reading map file /etc/auto.static
parse_init: parse(sun): init gathered global options: (null)
mounted indirect on /net with timeout 300, freq 75 seconds
st_ready: st_ready(): state = 0 path /net

[This is all the output I get, even after I try to access the server using "ls /net/www"]

Kernel version: Linux at 2.6.38-8-generic-pae #42-Ubuntu SMP Mon Apr 11 05:17:09 UTC 2011 i686 i686 i386 GNU/Linux
Autofs version: dpkg -l autofs*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Description
+++-======================-======================-============================================================
ii autofs 5.0.5-0ubuntu6 dummy transitional package from autofs to autofs5
ii autofs5 5.0.5-0ubuntu6 kernel-based automounter for Linux, version 5