This still happens with latest code from PEAR (updated to Kronolith 4.2.0)

Kronolith 4.1.4 from PEAR, with Kolab back-end.

Summary: When I re-open an event that had *no* alarm, it's changed to 
"create alarm, 0 minutes in advance". When I then (after saving) 
re-open, the alarm is set to "create alarm, 1 minute in advance".

Steps to reproduce:

1. create new event, make sure reminder is set to "don't create 
reminder" (it's default for this user, so no change required).
-> .../kronolith/saveEvent sends
"event=&cal=&lon=&lat=&zoom=&rstart=&rend=&isajax=1&sendupdates=1&recur_edit=all&title=test&start_date=19.02.2014&start_time=15%3A12&end_date=19.02.2014&end_time=16%3A12&timezone=&status=2&location=&targetcalendar=internal%7CYTozOntpOjA7czo4OiJqbW96ZHplbiI7aToxO3M6ODoiS2FsZW5kZXIiO2k6MjtzOjU6IklOQk9YIjt9&description=&alarm=0&alarm_value=15&alarm_unit=1&alarm_change_method=0&event_alarms_sound=&event_alarms_email=&recur=0&recur_daily=1&recur_daily_interval=&recur_weekly=1&recur_weekly_interval=&recur_monthly=1&recur_monthly_interval=&recur_yearly=1&recur_yearly_interval=&recur_end_type=none&recur_end_date=&recur_count=&eventurl=http%3A%2F%2F&kronolithEventAttendeesreal=&attendees=&resources=&kronolithEventResourcesreal=&kronolithEventTagsreal=&tags=&sig=2014021720140221&view=workweek&view_start=20140217&view_end=20140221&as_new=0&cstart=2014-02-16T23%3A00%3A00.000Z&cend=2014-02-20T23%3A00%3A00.000Z&token=xInxMPCDNBD-b-UG0-XPlQ5"

-> alarm=0 (probably "off"), alarm_value=15 (default value, was in 
entry field), alarm_unit=1 ("minutes"?)

2. klick on new event
-> .../kronolith/getEvent returns
{"response":{"event":{"t":"test","c":"YTozOntpOjA7czo4OiJqbW96ZHplbiI7aToxO3M6ODoiS2FsZW5kZXIiO2k6MjtzOjU6IklOQk9YIjt9","s":"2014-02-19T15:12:00","e":"2014-02-19T16:12:00","fi":true,"la":true,"x":2,"al":false,"pe":true,"pd":true,"l":"","mt":false,"id":"NTMwNGJiYWYtMWZjMC00ZjE2LTllZjEtMzNmMmMwYTg2NjA0","ty":"internal","sd":"19.02.2014","st":"15:12","ed":"19.02.2014","et":"16:12","tz":null,"a":"0","pv":false,"d":"","u":"","tg":[""],"gl":null}}}

-> a=0 (according to my tests this seems to be alarm time in minutes)

Clicking on the event's "reminder" tab shows "create, 0 weeks in advance"

3. add description and save event, without other changes
-> .../kronolith/saveEvent sends
event=NTMwNGJiYWYtMWZjMC00ZjE2LTllZjEtMzNmMmMwYTg2NjA0&cal=internal%7CYTozOntpOjA7czo4OiJqbW96ZHplbiI7aToxO3M6ODoiS2FsZW5kZXIiO2k6MjtzOjU6IklOQk9YIjt9&lon=&lat=&zoom=&rstart=&rend=&isajax=1&sendupdates=1&recur_edit=all&title=test&start_date=19.02.2014&start_time=15%3A12&end_date=19.02.2014&end_time=16%3A12&timezone=&status=2&location=&targetcalendar=internal%7CYTozOntpOjA7czo4OiJqbW96ZHplbiI7aToxO3M6ODoiS2FsZW5kZXIiO2k6MjtzOjU6IklOQk9YIjt9&description=testdescription&alarm=1&alarm_value=0&alarm_unit=10080&alarm_change_method=0&event_alarms_sound=&event_alarms_email=&recur=0&recur_daily=1&recur_daily_interval=&recur_weekly=1&recur_weekly_interval=&recur_monthly=1&recur_monthly_interval=&recur_yearly=1&recur_yearly_interval=&recur_end_type=none&recur_end_date=&recur_count=&eventurl=&kronolithEventAttendeesreal=&attendees=&resources=&kronolithEventResourcesreal=&kronolithEventTagsreal=&tags=&sig=2014021720140221&view=workweek&view_start=20140217&view_end=20140221&as_new=0&cstart=2014-02
-16T23%3A00%3A00.000Z&cend=2014-02-20T23%3A00%3A00.000Z&token=xInxMPCDNBD-b-UG0-XPlQ5

-> alarm=1 (probably "on"), alarm_value=0, alarm_unit=10080 (minutes per week)

4. open event again by clicking it and look at the reminder tab
-> .../kronolith/getEvent returns
{"response":{"event":{"t":"test","c":"YTozOntpOjA7czo4OiJqbW96ZHplbiI7aToxO3M6ODoiS2FsZW5kZXIiO2k6MjtzOjU6IklOQk9YIjt9","s":"2014-02-19T15:12:00","e":"2014-02-19T16:12:00","fi":true,"la":true,"x":2,"al":false,"pe":true,"pd":true,"l":"","mt":false,"a":1,"id":"NTMwNGJiYWYtMWZjMC00ZjE2LTllZjEtMzNmMmMwYTg2NjA0","ty":"internal","sd":"19.02.2014","st":"15:12","ed":"19.02.2014","et":"16:12","tz":null,"pv":false,"d":"testdescription","u":"","tg":[""],"gl":null}}}

-> a=1!

and reminder is set to "create, 1 minute in advance"

Already the first "open" changed the alarm setting from "off" to on 
for display, and it got sent to the server upon the subsequent save.