V 4.0.1 PTT hangs in transmit

I loaded V4.0.1 basic yesterday on to my 6600, performed the cold boot procedure, and I found that when I step off the footswitch the radio stays in transmit for 5-10 seconds before it goes finally goes back to recieve. Pressing the lighted MOX button during the event had no effect. I downgraded back to 3.10.15, the last version that worked perfectly for me.

I'm not looking for a fix or a "try this" since the software is no longer on the radio and the hassle of dealing with problems outweighs any of the improvements featured in 4.0.1 I would make use of. I just wanted to throw the info out there in case it is of use to someone.