In my case, the amount of gain deferral I was eligible for was only about $800. I just dropped it-- didn't defer and so didn't use the form. I figured deferring taxation on $800 wasn't worth the hassle of starting new somewhere else at that point.
Of course, my "replacement property" is no longer a replacement property for tax purposes, and its basis is established independently.
I'm glad I didn't have more at stake.
Good luck.
