I think I filed the wrong basis on my 2011 8606 form and I don't understand how to correct it.
Background:
Start - Rollover IRA with about $300,000
3/31/2011 - Made a $5,000 after-tax contribution to a new IRA for 2010
12/30/2011 - Converted money from both the rollover and new IRA. The portion from the new IRA was $1,750.
1/1/2012 - Made a $5,000 after-tax contribution to the non-rollover IRA for 2011
1/1/2012 - Made a $5,000 after-tax contribution to the non-rollover IRA for 2012
When I filled out the Taxable IRA Distribution Worksheet, it had me include the $5,000 contribution for 2010 plus the $5,000 contribution for 2011, even though that money wasn't in the IRA when I did the conversion. The net effect is that messed up my basis and made it look like I converted $3,458 of pre-tax dollars instead of the $1,750 that I really did convert.
Should I ignore the worksheet and file an amended return with a correct 8606 based on my calculations? Did I do something wrong by converting before making my 2011 contribution? I'm really not sure where to go from here, but I don't want to lose $1,750 in basis unnecessarily.