sometimes fails to start on edgy - 100% hang on 'scanning folders in "Exchange server..."'

It doesn't actually freeze, it just never leaves this state. It's generating no network traffic and uses 100% CPU (evolution-exchange-storage process)

2 entries in taskbar, bothing saying:
'scanning folders in "Exchange server 10.0.0.254" (...)'

My password is saved in the gnome password manager.

This happens on start-up once in a while. Strace and Ltrace show *no* output for that thread.

gdb gives me:
gdb /usr/lib/evolution/2.8/evolution-exchange-storage 5027
<snip>
(gdb) bt
#0 0xb6e9a3d7 in ?? () from /usr/lib/libglib-2.0.so.0
#1 0xb6ed50af in g_str_equal () from /usr/lib/libglib-2.0.so.0
#2 0xb6eac1e6 in g_hash_table_lookup () from /usr/lib/libglib-2.0.so.0
#3 0xb72ef4a1 in exchange_account_is_save_password () from /usr/lib/libexchange-storage-1.2.so.2
#4 0xb6f7c199 in g_cclosure_marshal_VOID__POINTER () from /usr/lib/libgobject-2.0.so.0
#5 0xb6f6f83b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#6 0xb6f7fc43 in g_signal_chain_from_overridden () from /usr/lib/libgobject-2.0.so.0
#7 0xb6f81167 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#8 0xb6f81329 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#9 0xb72f8bce in exchange_hierarchy_new_folder () from /usr/lib/libexchange-storage-1.2.so.2
#10 0xb72f7d87 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#11 0xb72f7eb3 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#12 0xb72f7eb3 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#13 0xb72f7eb3 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#14 0xb72f7eb3 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#15 0xb72f7eb3 in exchange_hierarchy_webdav_parse_folder () from /usr/lib/libexchange-storage-1.2.so.2
#16 0xb72f863c in exchange_hierarchy_scan_subtree () from /usr/lib/libexchange-storage-1.2.so.2
#17 0xb72f1f3d in exchange_account_rescan_tree () from /usr/lib/libexchange-storage-1.2.so.2
#18 0x0805ea43 in mail_stub_exchange_new ()
#19 0x08063b63 in mail_stub_get_type ()
#20 0xb6ee1d1d in g_io_channel_unix_get_fd () from /usr/lib/libglib-2.0.so.0
#21 0xb6eb8872 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0xb6ebb84f in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#23 0xb6ebbbf9 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#24 0xb718ca23 in bonobo_main () from /usr/lib/libbonobo-2.so.0
#25 0x0805b9a3 in main ()