Why Does Mimic Delete Frames in My Animation?

Open the .PZ2 in a text editor. Near the beginning of the file you'll see a section labeled "movieInfo".

Example:
{
version
{
number 3.0
clearFigureKeys 134
movieInfo
numFrames 134
framesPerSec 30
soundFile
Temp3Sabrinaconnery1.wav
0 0
}
actor head:1
{
channels

Delete the entire movieInfo section, brackets and all, and save the edited file to the Library folder.

Example:
{
version
number 3.0
clearFigureKeys 134
actor head:1
{
channels

Now you can apply the pose file anywhere in the timeline. You'll need to splice the audio files together and import them into Poser manually.