Formatting changing constantly in Word

[sitash]

I am using word 2007. Everytime I open a saved document on the same computer with the same printer the formatting in my document has changed. Mostly the tabs are in different places, the spaces in between paragraphs have turned into big gaps and sentences that previously fitted on one line have shifted onto two lines and I can't get them back to their original positions. Any idea's on what is happening in my system. Thanks heaps!

[OTPM]

Hi Sitash
Without seeing your document it is difficult to respond. If there is nothing sensitive in it are you able to save it as a Template (in order to retain formatting etc) and post it so we can have a look for you.
Tony