Hey, nice spreadsheet.  Two minor questions: 

1) Isn't the provision for taxes on the income statement actually the taxes 
on the 'income' they made from using the sales method (equal to 46%), rather 
than what they pay will actually pay the IRS under the installment method?  I 
think the notes show how instead of paying the 4.1$ based on their recognized 
income, they pay some itty bitty amount based on installment.  If so, I think 
they actually get a 46%  tax break on the 1 million and change that they lose 
using a cash basis.  Still a loss, just not so big.  Anyway, I'm not sure if 
I'm thinking straight on this, but that's how I read the numbers.

2) Does the balance sheet have to change a little?  For example, does 
shareholder equity change since the income that goes to retained earnings is 
now a loss, rather than a gain?  Also, if revenue is recognized on a cash 
basis and is now much smaller, there needs to be another liability to equal 
out the decrease in revenues with the still large notes receivables on the 
asset side (as you note in the answer the notes recievables stays the same).  
Seems like they might need a liability like "deferred profits" or some such 
thing, such that the ["deferred profits" +  revenues (recognized on cash 
basis)] = notes receivables.

Anyway, I may not have this right, but thought I'd bring it up to see what 
you think.

Best,
Jeff