Spark thrashing CPU and can't be used

In the last few days Spark 2.6.3 on my work Dell E6400 laptop running XP Professional has started behaving rather badly. Usually it starts up ok but, if I attempt to start a conversation or sometimes seemingly randomly, it starts to use up to 50% of the CPU (I have a dual core processor) and the program is unresponsive, meaning it is impossible to use IM. As I use IM a lot for my work this is a big problem for me. I am not aware of any significant changes to my software config that might have caused this although the corporate IT department does use LANDesk to silently push updates so it can’t be ruled out.

I’ve done a bit of searching about this problem before posting this and I do have some quite large transcript files (including 4 that are over 1Mb and quite a few that are between 300 & 650Kb) which someone on another thread suggested could be a contributing factor. However I am very reluctant to delete these if it can be avoided.

Can anyone suggest any ways in which I can resolve this or perform further diagnosis to help find a resolution as this is becoming a major productivity blocker for me?

Since you mentioned you have a laptop, do you suspend the laptop while Spark is connected to the chat server? I have seen the exact same behavior that you described on my Core i7 equipped Dell laptop if I forget to turn off Spark before I put the laptop to sleep.

No - I rarely, if ever, suspend the laptop so I am fairly sure that is not the problem. What I see is actually quite similar to the question posed in this thread around the same time I posted my own:

http://community.igniterealtime.org/thread/48658?tstart=0

What if you just rename or move those particular transcript files?