When I upgraded to VA 7.42 for use with LM v4.5, ATC and the first officer communicate perfectly on the ground and through the departure phase of the flight with ATC giving instructions and the first officer repeating those instructions and ending with the identifying flight number.  Once ATC instructs the pilot to contact "center" on "xxx.xx" frequency, the first officer will repeat the frequency but the frequency changes so quickly that the identifying flight number is cut off.  Sometimes the the frequency changes prior to the completion of the complete frequency (e.g. "Contact Cleveland Center on 134.7.....").  After a brief pause (usually long enough for the missing portion of the transmission), the first officer will make contact and Center responds.  This only happens during the enroute phase when changing Center frequencies.  Any ideas?  

Yep, this is a known bug that has been reported to the developer, but since it involves only certain comms in FO mode (not the common mode for the use of VOXATC), it hasn't been addressed even in 7.43. My limited experience with it is that the AI tunes to the new comm frequency before the previous phrasing is complete. No one here has discovered a workaround like for example, tinkering with sound output device settings in the Windows Control Panel.

You should report the bug via the official VOXATC website contact page as there is another update coming.

Thanks for responding.