WebKit causing programs to crash...?

Question

I'm using an intel-based Macbook Pro (2.33GHz core 2 duo, 3 GB RAM) with OS X 10.5.8. I recently upgraded to Lightroom 3 and Photoshop CS5, and just a couple of weeks ago downloaded the 12.0.1 PS update.
PS started crashing on me a lot. It happens in HDR Pro or when I'm using the new Mixer Brush. Sometimes just trying to get PS to merge images in HDR Pro will do it (I never even get to the editor), sometimes I get the editor, but it crashes before I can finish the edit and create the tone-mapped image. When using the mixer brush, I can work for 30 or 40 minutes sometimes, and then PS is gone. I posted the crash reports on Adobe's CS5 forum. and the employee who responded said the reports are different (always thread 0 that crashes, but the crash seems to be different), it means the heap is being corrupted but they couldn't tell where or when from the crash reports. End of discussion, unfortunately.
It was then that I discovered that Lightzone wouldn't start. It said it "encountered an internal error." It didn't matter if anything else was running or not, and I haven't been able to get it up since (all this in the past 2 weeks). Lightcrafts asked to see the log file Lightzone keeps, and said the log indicates the problem is in WebKit. They wanted to know if I was using a Safari beta, which I'm not. I got back on the Adobe forum and asked if PS uses WebKit, which it does.
I re-installed Lightzone, in case something had been corrupted in the file. No help. And it seems a bit unlikely that all this (both LZ and PS crashing) would be unrelated. It also seems unlikely to me that PS could do anything to the system that would permanently change it so another program couldn't start (even after restarting the computer several times and PS--or anything else I'm aware of--not up and running). So now it's looking like the OS.
I have my system set to automatically check for updates, and I don't pay too close attention, only to glance at it and note that it is a system update, or iTunes, or a security update, or...), so I don't remember if OS X was updated recently. However, is some recent update to WebKit causing my programs to fail?
Thanks,
Michael

Answer 1

A further update… My wife found a site where others were complaining about various problems after upgrading to Snow Leopard. I had not been looking at sites complaining about Snow Leopard, because I didn’t upgrade and am still using Leopard (10.5.8). But, any port in a storm. The site mentioned two possible solutions others had used. The first was to safe boot and then try to use the program that had been failing (I’m not sure trying to use the offending program has anything to do with it—I think it’s just the safe boot that’s important). If it worked, then boot normally and try to use the program again. I did this, and Lightzone has been opening fine ever since. Also, oddly, Photoshop has stopped crashing on me.
The site says that what’s happening is that all the permissions are being re-written on safe boot. Kind of makes sense for Lightzone, which couldn’t even open, but is harder to see fro PS. Maybe it’s about permission to access memory, which seems odd. Well, I wouldn’t really know either way, but it seems to have worked.