Decagon CTD and Arduino Mega issue

Hi
I am using the SDI-12 library to collect data from a single Decagon CTD with a Mega. The CTDs were purchased within the last one year. I have a mysterious fail in our code that was working for the better part of 9 months. The only changes that have occurred is that we ported our code to a PC from a Mac, and installed the latest available version of your SDI-12 library. The compiled binaries went from a PC-based Arduino IDE. The primary issue seems to be timing, the CTD outputs a signal but the Arduino does not seem to pick it up. I have used a delay from 380 ms (per CTD manual) to 2000 ms with no sucess. All this while, each of these CTDs work well with our Campbell logger. Our original working version used a 500 ms delay after “send”
I was wondering if you have come across of any issue like this?. We even went back to the older version of your library that we downloaded last year, and it did not seem to help. Testing the different flavored ” SDISerial ” library did not help either. I would appreciate it if you can point me towards a solution. The code we have built is based off of example code from your library, with an additional SD card write option. But stripping it down to the bare minimum test code also has provided no response. I would be happy to post it if necessary.

1. Would this have to do with the other dependent libraries, such as “SoftSerial”?
2. The CTDs were tested with an address of “0” or “1”. Should this be expanded to more addresses?
3. The CTD is continuously powered, should power be cycled? They work well previously, and totally fine like this with the CR1000.

Due to technical issues I cant go back to a Mac, but I am not sure if that is the cause of this issue.

Any tips will be greatly appreciated.
Thank you
GM