I noticed the same thing today. I was on flt#38, IAH-EWR.

The pda site shows 8 of 16 upgraded to F, but continental.com shows only 2 upgraded (they are also among the 8 listed on the PDA site).

On the other hand, for that same flight, the Flight Standby List for both co.com and the mobile site are exactly the same (3 pax cleared).