I was experiencing the same problem and made the change to the Excel 2007 Registry entry as shown but still it has to configure each time I start Excel. None of my other Microsoft Office 2007 applications do this.
After performing the change suggested I exported the HKCU\Software\Microsoft\Office\12.0\Excel\Options registry entries which are listed below. Any other ideas to solve the problem would be appreciated.
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Options]
"FirstRun"=dword:00000000
"SP1FirstRun"=dword:00000000
"OptionsDlgSizePos"=hex:48,03,00,00,ad,02,00,00,a4,01,00,00,b7,00,00,00,00,00,\
00,00
"DefaultSheetR2L"=dword:00000000
"UseSystemSeparators"=dword:00000001
"ThousandsSeparator"=","
"DecimalSeparator"="."
"Options95"=dword:00000001
"OptionFormat"=hex:00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00
"Pos"="176,232,1260,764"
"TipShown"=hex:00,00,00,00,00,00,00,00,02,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
"NoReReg"=dword:00000001
"StickyPtX"=dword:00000185
"StickyPtY"=dword:00000108