Experiencing problems with audio in timeline, any solutions ?

[Recco]

I was using WMM to edit videos and it worked fine, but when I got new computer, I was having following issues...
-Audio (song) length in timeline differs from the original, sometimes shorter, sometimes longer (even doubled), when I just play the song it works, but it´s imposible for me to sync the video with audio, when timeline isn´t accurate.
-I tried Cyberlink Powerdirector in hope that it´ll work. Audio length matches, but when I pick moment in timeline (Without video, just song in Audio trail) it´s off by 5-30 seconds !!
Since I´m having similar problem with both, I´m guessing it has to do something with codecs I use.
PS: I´ve already tried compatibility and filter based solutions.
Help would be appreciated.

[aedipuss]

check your source audio files. if they are vbr or an odd format, then try converting to wav before using them for video work.

[Recco]

I´ve already tried that, In prewiev mode the length matches, but in timeline it´s 40seconds shorter than original ...
But thanks anyway.

[Recco]

I´ve downloaded new codecs (No Divx) and .wav file works normally for Powerdirector (Mp3 etc. still same issue)
I can at least start working now, but still I would appreciate solutions.