Thank you for taking the time to reply to my post... I really appreciate it.  To answer you question, I'm using all the coper ports on each switch (te1/0/21-24 and te2/0/21-24).  After pulling my hair for a while, I went back to basics and checked on support.dell.com any ... to my surprise, V5.1.7.5 was released on Jan 29. Open the release notes and this issue is specifically mentioned.  I applied the update and VOILA, I'm able to create my LAG ports. Without issues.  Thanks 
I have 2 8024F switches in one stack.   I want to use interface 1/0/21-24 and 2/0/21-24 to be part of the same port channel. Is this possible? When I try do this, I get the following error.  "Row Number 23: Error! LAG members do not have same speed, duplex or auto-negotiation settings." Thanks 
8024f LAG across stack members