Micrsoft Office:mac Excel
From time to time this Application refuses to Quit and usually a window pops up informing me that there is an error "-1712". I can cure it by switching off the computer and then switching on at which stage the application works without any problems for quite long stretches until it decides to Quit for no apparent reason. I would be grateful for any thoughts on this. This is with Mac OS v10.6 installed I got into 10.5 by mistake.
iMac, Mac OS X (10.6.8), 2.5GHz Intel 15, 4Gb 1333 MHz DDR3