PDF form is missing information entered on a Windows PC

I have a 3rd party form which has a lot of fields to be filled in. I started entering the information on a Windows PC and saved it to Dropbox. When I open the form in Apple Preview on my OS X Yosemite machine the fields that I filed in are all blank! If I open it in Adobe Reader instead the information is present but when I save the file and open it in Windows again all of the previously saved information from my initial Windows session has gone. Please tell me how I can stop this happening as I use these forms on a regular basis and I need to edit them in Windows 7 and Mac OS X Yosemite.