I too have this evolution migration problem.  I backed up my settings on a Fedora 8 x86_32 paltform and performed a bare metal install of Ubuntu Intrepid 8.10 x86_64 on the same hardware.  Started evolution, started a restore from the backup, and it did the silent fail scenario.

Reading this report, I added the source for the ppa patches, updated my machine and stopped the background tasks ( # evolution --force-shutdown). Removed the .evolution directory and started evolution then proceeded to restore the fedora.generation backup file; again it unpacked the backup file, started converting the folders, then failed silently.

I then opened a console window, and started evolution - again it failed, but I got error messages:  

** jscott@vserv:~$ evolution
(evolution:19600): camel-WARNING **: camel_exception_get_id called with NULL parameter.
GLib-ERROR **: /build/buildd/glib2.0-2.18.2/glib/gmem.c:136: failed to allocate 31774537744 bytes
aborting...
Aborted
** jscott@vserv:~$ 

Here is a listing of my backup file: 

** jscott@vserv:~$ ll Downloads/evolution-backup-20090109.tar.gz 
-rw-r--r-- 1 jscott jscott 360324196 2009-01-09 22:44 Downloads/evolution-backup-20090109.tar.gz
** jscott@vserv:~$ 

Here is a gdb listing:

(no debugging symbols found)
... trimmed ...
(no debugging symbols found)

(evolution:19657): camel-WARNING **: camel_exception_get_id called with NULL parameter.
[New Thread 0x40d57950 (LWP 19667)]
[Thread 0x40d57950 (LWP 19667) exited]
[New Thread 0x41558950 (LWP 19668)]
[Thread 0x41558950 (LWP 19668) exited]
[New Thread 0x41558950 (LWP 19669)]

GLib-ERROR **: /build/buildd/glib2.0-2.18.2/glib/gmem.c:136: failed to allocate 31774537744 bytes
aborting...

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x41558950 (LWP 19669)]
0x00007fdd8e40ffd5 in raise () from /lib/libc.so.6
(gdb) thread apply all bt

Thread 4 (Thread 0x41558950 (LWP 19669)):
#0  0x00007fdd8e40ffd5 in raise () from /lib/libc.so.6
#1  0x00007fdd8e411b43 in abort () from /lib/libc.so.6
#2  0x00007fdd8e792d9e in g_logv () from /usr/lib/libglib-2.0.so.0
#3  0x00007fdd8e792e33 in g_log () from /usr/lib/libglib-2.0.so.0
#4  0x00007fdd8e79148a in g_malloc () from /usr/lib/libglib-2.0.so.0
#5  0x00007fdd987230e0 in ?? () from /usr/lib/libcamel-provider-1.2.so.14
#6  0x00007fdd82f1931e in ?? () from /usr/lib/evolution-data-server-1.2/camel-providers/libcamellocal.so
#7  0x00007fdd98721573 in camel_folder_summary_migrate_infos () from /usr/lib/libcamel-provider-1.2.so.14
#8  0x00007fdd88a94ad2 in ?? () from /usr/lib/evolution/2.24/components/libevolution-mail.so
#9  0x00007fdd88a94c26 in ?? () from /usr/lib/evolution/2.24/components/libevolution-mail.so
#10 0x00007fdd8e7b2264 in ?? () from /usr/lib/libglib-2.0.so.0
#11 0x00007fdd958763ea in start_thread () from /lib/libpthread.so.0
#12 0x00007fdd8e4c3c6d in clone () from /lib/libc.so.6
#13 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fdd9bb80790 (LWP 19657)):
#0  0x00007fdd8e4ba206 in poll () from /lib/libc.so.6
#1  0x00007fdd8e78c3a8 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007fdd8e78c6cb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007fdd88a948cc in ?? () from /usr/lib/evolution/2.24/components/libevolution-mail.so
#4  0x00007fdd88a963b8 in em_migrate () from /usr/lib/evolution/2.24/components/libevolution-mail.so
#5  0x00007fdd88aa3e0e in ?? () from /usr/lib/evolution/2.24/components/libevolution-mail.so
#6  0x00007fdd9b7a7f94 in GNOME_Evolution_Component_upgradeFromVersion () from /usr/lib/evolution/2.24/libeshell.so.0
#7  0x000000000040da87 in ?? ()
#8  0x000000000040dfc7 in ?? ()
#9  0x000000000040e12d in ?? ()
#10 0x0000000000415813 in ?? ()
#11 0x00007fdd8e788d3b in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#12 0x00007fdd8e78c50d in ?? () from /usr/lib/libglib-2.0.so.0
#13 0x00007fdd8e78ca3d in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#14 0x00007fdd930068a6 in bonobo_main () from /usr/lib/libbonobo-2.so.0
#15 0x00000000004154b2 in ?? ()
#16 0x00007fdd8e3fb466 in __libc_start_main () from /lib/libc.so.6
#17 0x000000000040a639 in ?? ()
#18 0x00007fffa3bd1018 in ?? ()
#19 0x000000000000001c in ?? ()
#20 0x0000000000000001 in ?? ()
#21 0x00007fffa3bd16e0 in ?? ()
#22 0x0000000000000000 in ?? ()
#0  0x00007fdd8e40ffd5 in raise () from /lib/libc.so.6
(gdb) 

The error message has been consistent through several different attempt,i.e. removing all or portions of the .evolution directory, reinstalling, etc.

Note to verify the backup, I started a Fedora 32bit VM and restored it successfully  -- 32bit to 32 bit works.  32bit to 64bit fails.

I am creating another VM now of Intrepid x86, to see if I can restore it to a 32bit Intrepid and then restore that file on my 64bit desktop.

If there is a solid fix for this problem, and I missed it somehow -- please advise.  Otherwise, I'm in wait mode.