Firefox hogging processor sometimes on startup

[Colin Law]

I have mentioned this before, sometimes when FF starts up it functions
ok but consumes masses of CPU, eventually hogging the whole machine.
I can close FF but the process does not die, I have to kill it.  I
have started running the console on startup and this time the last
thing I see in the log is shown below.  Is it possible that the
problem is related to google calendar syncing?

Colin

Reminderfox  ** Alert **    2014-04-25 21:50
rmFx_CalDAV_SyncActiveAccounts  trace: addReminderDialog: ' start sync
in background for Remote Calendars'
chrome://reminderfox/content/caldav/calDAVcalls.js # 284
1: [chrome://reminderfox/content/addReminderDialog.js # 770]
rmFx_mainDialogLoad/<

PROPFIND https://clanlaw%40googlemail%2Ecom@www.googleapis.com/caldav/v2/clanlaw%40googlemail.com/events/
[HTTP/1.1 207 Multi-Status 393ms]
Reminderfox  ** Alert **    2014-04-25 21:50
.core.clearRemindersAndTodos
chrome://reminderfox/content/reminderFoxCore.js # 2670
1: [chrome://reminderfox/content/reminderFoxCore.js # 5439]
reminderfox.core.importRemindersUpdateAll

POST https://mail.google.com/mail/u/0/ [HTTP/1.1 200 OK 335ms]
Reminderfox  ** Alert **    2014-04-25 21:50
rmFx_CalDAV_SyncActiveAccounts  trace: addReminderDialog: ' start sync
in background for Remote Calendars'
chrome://reminderfox/content/caldav/calDAVcalls.js # 284
1: [chrome://reminderfox/content/addReminderDialog.js # 770]
rmFx_mainDialogLoad/<

PROPFIND https://clanlaw%40googlemail%2Ecom@www.googleapis.com/caldav/v2/clanlaw%40googlemail.com/events/
[HTTP/1.1 207 Multi-Status 77ms]
Reminderfox  ** Alert **    2014-04-25 21:50
.core.clearRemindersAndTodos
chrome://reminderfox/content/reminderFoxCore.js # 2670
1: [chrome://reminderfox/content/reminderFoxCore.js # 5439]
reminderfox.core.importRemindersUpdateAll