QUOTE(Waiting4GC @ Nov 14 2007, 12:12 AM)

You should have filed 3 months prior to the expiration of your Conditional Permanent Residence card. Three weeks prior was too late.
Not true. You have 90 days to file. If you file after your card expires, that's when you have trouble.
from the filing instructions on the I-751 form itself:
QUOTE
When Should I File the Form I-751?
. Filing jointly. If you are filing this petition jointly with your spouse, you must file it during the 90 days immediately before the second anniversary of the date you were accorded conditional resident status. This is the date your conditional residence expires.
. Filing with a request that the joint filing requirement be waived. You may file this petition at any time after you are granted conditional resident status and before you are removed.
. Effect of not filing.
If this petition is not filed, you will automatically lose your permanent resident status as of the second anniversary of the date on which you were granted conditional status.