As Sqgs pointed out, it's a procedure.

If you carefully check the 1-94, it's one year after the entry date, and is irrelevant to your H1b expiration date.
CBP simply extends one year without necessarily knowing your other non-immigration status, such as H,L.
However, it won't affect your status after one year. You are good to use H1 for work and AP for re-entry next time--you will get another one year parole period.
Check PJ's blog, more answers will come up to clear your doubts.

所有跟帖： 

• Why my AP expired half year after the entry date, not 1 yr? -waitfor485- ♀ (13 bytes) () 02/14/2008 postreply 07:55:55

• usually is one year after entry date. -pharmacyelite- ♂ (0 bytes) () 02/14/2008 postreply 12:18:48