That's a good thought, but I just tried it. Excel won't even let me finish typing it before it declares an error. Clearly it *wants* either a space or a comma as a separator, and it recognizes the arguments as distinct arguments if I use either of those syntax (which I can tell from the way the wizard is acting), but then it refuses to accept the resulting function for some reason.

I tried running Excel in safe mode, then Windows in safe mode, because of suggestions I saw in other people's threads. The first made no difference, but the second wouldn't even let me boot Excel; gave me a setup error of "Multiple ARP entries found for product".

Microsoft Excel 2010 (14.0.6117.5003) SP1 MSO (14.0.6123.5001)
Part of Microsoft Office Home and Business 2010
This product is licensed to: Hewlett-Packard
Product ID: 01631-237-4701036-11266

OS Name Microsoft Windows 7 Home Premium
Version 6.1.7601 Service Pack 1 Build 7601
System Manufacturer Hewlett-Packard
System Model HP Pavilion dv6 Notebook PC
System Type x64-based PC
Processor AMD A8-3500M APU with Radeon(tm) HD Graphics, 1500 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Hewlett-Packard F.1C, 5/12/2011
SMBIOS Version 2.7
System Directory C:\Windows\system32
Hardware Abstraction Layer Version = "6.1.7601.17514"
Installed Physical Memory (RAM) 6.00 GB