I have the newest Logos release on the Mac (4.5b sr3). I'm running OS X ver 10.7.4 on a dual core 3 GHz MBP w/ 4 GB of RAM (1 GB free as I experience my problem). It's a 3.5 yr old machine, so not the fastest thing out there, but it's been fine up until this release.
As I type in Notes, very frequently it stops, I get the spinning rainbow while nothing happens, then it catches up, filling in the text I was typing as I waited for the UI response.
When I look at the Activity Monitor, it appears as though Logos is pegging a core. And it happens at a pretty regular interval, it's almost like it's one second of use and one second of acting frozen.
The other stats don't look unusual. Disk Activity is minimal (though there is a little bit of writing happening while it hangs, but way below any sort of bottleneck threshold). Network Activity is nil.
CPU does not budge when I'm not using Notes and my system remains responsive. If I start typing anywhere else in the program, I do not see this hangup.
Bill