I use Photoshop CS4 and Lightroom 2. I recntly upgraded to 10.5.8 and began to have issues with LR. So, I reinstalled and downgraded my OS. I'm now running 10.5.2 on my MacBook 2.4G Core Duo with 4G RAM.
Everything works fine now, but the downgrade also resulted in having only Safari 3.0.4 and and older version of iTunes. I can't upgrade either of those until I upgrade the OS but I'm reluctant to do so because I might have problems again. Any suggestions? Install 10.6 instead? What kind of issues can I expect from that?