Yes, I would recommend anyone approach this with caution. I originally upgraded to the 1800mah cells without a problem. After reading about the 2800 mah I decided to go that route and now it appears the power board is having a problem. To be fair, I was seeing odd charging behavior starting a few days prior to my latest upgrade so it could be coincidental, but everyone should be cautious. My background is in electrical engineering so I knew what I was doing, but issues can always pop up. Be careful. Now I just need to beg iRex to sell me a power board!
P.S. Kudos to jharker for offering assistance with software code to help in the troubleshooting process. Thanks again.