Switching companies during I-140 processing

[Stellar]

• My H1 petition is till Feb 2008 currently but 6 years on H1 is till Nov 2008 since my original petition was approved in Nov 2002
• My Green card processing has been filed. Labor was approved in Oct 2006 and currently I-140 is in processing stage, with I-140 filed in Jan 2007
• I am thinking of moving to another organization and this may take a few months

My questions -
1) Is it advisable to wait till I 140 is approved in my current organization, or does that carry no weight since Labor is already approved?
2) Since it will take time to start processing GC again in the new organization, given my H1 dates above, what is the latest date by when the new organization should file for I -140 or subsequent stage? I need this to time my move
3) There was something of 1 more year of H1, can I extend my H1 by 1 year to 2009 and thus give myself more time to switch to another company?

[phongnguyen17]

Ask your new employer fills LC and I-140 for you before switch to him for safe.