I have been enjoying this version for some time without any issues. However, of late, I have had trouble quiting the program, get spinning wheel, and it either gives me a spinning wheel and won't load, or it will tell me that it can only load files in Read Only mode. I can sometimes shut down the iMac and it will load fine after those problems. So the issues seem somewhat intermittent. I am running Snow Leopard on this old iMac, and will upgrade to a new iMac within the next few months. But for now, I would like to keep using JRiver for Mac on my old computer until I have enough funds to upgrade. I am wondering if I could get past this newly acquired problem if I try to upgrade my version of JRiver. I don't see a newer version of 20 to upgrade to, only see Version 21. Can I install version 21 on my old iMac or is that asking too much of this old pc and Snow Leopard? Thanks in advance for any thoughts on this problem.