All chat histories end on July 18, 2011 - which was the date of the update.
There is no way to see chat history from July 18 to current, and new chat historys do not seem to be saving.
I have tried changing the “disable chat history” in general chat settings back and forth a couple of times - didn’t fix.
Tried re-install - didn’t fix.
See here http://community.igniterealtime.org/message/216097#216097
Look at your XML hystory files and check tags in it.
How do I look at XML History files?
APC,
Disable Chat History then adding back worked for me, you can always try this. What I did was in Spark>Preferences within Chat I check Disable Chat History, and also Disable showing previous conversation in chat, and clicked Apply, logged out of Spark and then back in and removed both check marks save. Note that this will remove any previous chat history that you may have or is important. You may want to backup your transcript before doing this, if you are using Windows 7 your history should be in C:\Users\user.name\Spark\user\user.name@domain.name\transcripts in Windows XP it will be in similar folder.
JDS