I've just tried to import (from SOGo's web interface) the event (by surrounding it with BEGIN:VCALENDAR and END:VCALENDAR tags) and it works as expected.

Do you have a clean example that you can't import?

I want the real ICS file, not modified in any way.

Hello,
here you are complete example (example.ics) of that calendar. I have tried it right now and sogo immediately crashed.

I've just tried and it works as expected for me.

Try to run SOGo with only one process. Attach to the child process using gdb and produce a stack trace.

Install the SOPE/SOGo/GNUstep debugging symbols prior doing this.

this is what you have asked for?

#0 0x004a4416 in __kernel_vsyscall ()
0000001 0x00d545bb in poll () from /lib/libc.so.6
0000002 0x01187510 in -[GSRunLoopCtxt pollUntil:within:] (self=0xa08127c, _cmd=0x1319df0, milliseconds=499, contexts=0xa14db44) at GSRunLoopCtxt.m:423
0000003 0x010bed73 in -[NSRunLoop acceptInputForMode:beforeDate:] (self=0x9f5b284, _cmd=0x1319e10, mode=0x1319538, limit_date=0xa072234) at NSRunLoop.m:1198
0000004 0x010bf174 in -[NSRunLoop runMode:beforeDate:] (self=0x9f5b284, _cmd=0x7f25a8, mode=0x1319538, date=0xa072234) at NSRunLoop.m:1266
0000005 0x006d3450 in -[WOWatchDog run:argc:argv:] (self=0x9f62ba4, _cmd=0x7f2620, newAppName=0x8050280, newArgC=7, newArgV=0xbfb72194)
at WOWatchDogApplicationMain.m:922
0000006 0x006d3bdb in WOWatchDogApplicationMain (appName=0x8050280, argc=7, argv=0xbfb72194) at WOWatchDogApplicationMain.m:1028
0000007 0x080492e5 in main (argc=7, argv=0xbfb72194, env=0xbfb721b4) at sogod.m:53

OK, sorry, new complete debug output (probably the right - previous post ignore pls) attached as "sogo-debug.log"

Please show us the exact list of installed SOPE and SOGo packages.

here you are:
[user@gw ~]$ rpm -qa | grep sogo
sogo-debuginfo-1.3.14-1.centos6.i686
sogo-1.3.14-1.centos6.i686
[user@gw ~]$ rpm -qa | grep sope
sope49-xml-4.9-20120323_1664.el6.1.i686
sope49-ldap-4.9-20120323_1664.el6.1.i686
sope49-gdl1-mysql-4.9-20120323_1664.el6.1.i686
sope49-core-4.9-20120323_1664.el6.1.i686
sope49-gdl1-contentstore-1.3.14-1.centos6.i686
sope49-debuginfo-4.9-20120323_1664.el6.1.i686
sope49-mime-4.9-20120323_1664.el6.1.i686
sope49-cards-1.3.14-1.centos6.i686
sope49-gdl1-4.9-20120323_1664.el6.1.i686
sope49-appserver-4.9-20120323_1664.el6.1.i686
sope49-sbjson-2.3.1-20120323_1664.el6.1.i686
[user@gw ~]$ rpm -qa | grep gnustep
gnustep-make-debuginfo-2.6.1-1.i686
gnustep-make-2.6.1-1.i686
gnustep-base-1.23.0-1.i686
gnustep-base-debuginfo-1.23.0-1.i686

I seem to have a similar issue with recurring events (imported from Outlook 2010, which most likely has received some events from a Nokia Symbian phone) which I reported a few hours ago:
http://www.sogo.nu/bugs/view.php?id=1772

I just tried importing the export.ics attached to this issue and I can confirm that my SOGo 1.3.12c crashses also after importing the ics file and reloading the calendar. This is what I see in my sogod.log:

<snip>
[13/Apr/2012:00:40:56 GMT] "POST /SOGo/so/testeri2@mydomain.com/Calendar/weekview?day=20120413 HTTP/1.1" 200 1930/0 0.012 22311 91% 76K
stack smashing detected : /usr/sbin/sogod terminated
======= Backtrace: =========
/lib/i686/nosegneg/libc.so.6(__fortify_fail+0x4d)[0x62b62d]
/lib/i686/nosegneg/libc.so.6[0x62b5da]
/usr/lib/libNGCards.so.4.9[0x67b8824]
/usr/lib/libNGCards.so.4.9[0x67aaf1d]
/usr/lib/libNGCards.so.4.9[0x67b3e89]
/usr/lib/libNGCards.so.4.9[0x67ae38d]
</snip>

pepelton: thanks! I am happy that I am not the only person with same issue. :)
yes... and when I try to delete that record (i.e. via CalDAV from Thunderbird) sogo crashing disappear and everything is back in normal.

Please update to a nightly build and test it. We pushed a fix yesterday that might also fix the issue you have.

solved! thank you! importing example.ics does not going to sogo crashing anymore! :)

...of course with updating to nightly build :) (today from sogo rhel nightly repo)