T28P Call merging

[Netpro25]

Hello,

Several of my clients, using Asterisk, are running into issues with calls merging.

On the T28Ps, the BLF keys are set as park buttons.
Also, this issue occurs on all our phones, regardless of firmware and rebooting, the issue still remains.
The issue can be easily reproduced, when wanted.

Issue:
Basically, it occurs if an individual receives a call, places it on hold, then goes a head to pickup up another call residing in the parking lot (BLF buttons).
Once the BLF button is pushed, the call that was on hold is merged with the call on the parked (BLF) button.
Then, the call hangs up, meanwhile the call that was on hold and the call that was the BLF button are now able to communicate.

There is a work around for this, which we found, but it is not something we would like to continue doing.

Work-around:
While an individual is on hold, if we pick a different line key, than the one we are currently on, before picking up the parked call. The calls will not be merged.

Is there anyway we can change this functionality, so that when a parked call (BLF key) is picked up.
The parked call is not automatically merged with a call that is currently on hold.
This is a huge issue with some of our clients, since their clients or providers are now speaking with each other.

This thread sounds very similar to my issue: http://forum.yealink.com/forum/showthread.php?tid=1228
Just found it after creating this thread.

Thanks for any assistance provided!