WowAce

What steps will reproduce the problem?
1. First use on a mid-level hunter (fresh saved variables). Go into the Blizz Options panel and leave everything there set as default.
2. Then, press the "Test" button.

What is the expected output? What do you see instead?
Expected, a test to happen. Instead: an error is thrown up.

What version of the product are you using?
v0.2.0b

Do you have an error log of what happened?
["message"] = "YssCompare-0.2.0\\YssCompare.lua:5: attempt to concatenate a boolean value\nYssCompare-0.2.0\\YssCompare.lua:1339: in function <Interface\\AddOns\\YssCompare\\YssCompare.lua:1337>\n(tail call): ?:\n<in C code>: ?\n<string>:\"safecall Dispatcher[3]\":9: in function <[string \"safecall Dispatcher[3]\"]:5>\n(tail call): ?:\nAceConfigDialog-3.0-36:794: in function <...nfig-3.0\\AceConfigDialog-3.0\\AceConfigDialog-3.0.lua:609>\n(tail call): ?:\n<in C code>: ?\n<string>:\"safecall Dispatcher[4]\":9: in function <[string \"safecall Dispatcher[4]\"]:5>\n(tail call): ?:\nAceGUI-3.0-28 (Ace3):305: in function `Fire'\nAce3\\AceGUI-3.0\\widgets\\AceGUIWidget-Button.lua:23: in function <...dOns\\Ace3\\AceGUI-3.0\\widgets\\AceGUIWidget-Button.lua:22>\n\n  ---",
            ["type"] = "error",
            ["session"] = 2030,
            ["counter"] = 1,
        }, -- [838]

Please provide any additional information below.
USEnglish client/server, WoW 3.2.2a live.