Started working in US with A (consulting) from 2005 on H1B.
Applied for I140(EB3),I485 in 07/2007,I140(EB2) in 11/2007.
I140(EB3),I140(EB2) aprvd in 05/2008 & 09/2008.
Transfered H1B to B (consulting) in 07/2008.Worked upto 09/2008.
Moved to C (bank) on EAD in 09/2008.
Was advised to file AC21 on RFE, to avoid complications.
C was bought by D (bank) in 07/2010.
Not clear info about HR contacts in D for immigration, not filed AC21.Waiting for RFE, when PD became current.
PD current in 08/2010 & I485 aprvd for me,spouse on 08/03/2010.
Comp. A have no employees from 08/2008 and may exist without office & staff.Not sure about status.
Similar job in A, B, C, D(software developer)
Q.Do you forsee any issues for GC renewal/citizenship for not filing AC21 when changing jobs?