6.0.2b5 Sudden CPU jump

[ilia]

Was editing a set, deleted some unused tracks, suddenly started getting crackles, undid the delete, crackles continue, then abruptly CPU usage jumped to over 200% (normally - 65% on that set), playback a mess, finally able to stop it, CPU usage still >200%, turned off some questionable plugins, CPU still at around 140%. Disabled audio, saved the set, restarted Live, reloaded and deleted same tracks -- all is fine.