Ok....Im a newbie so i suppose this is the right forum to ask about this.

I recently bought a Sony DVD RW DRU-510A, I recieved ArcSoft Showbiz with it and have just been using it for basic editing.
This has worked fine...untill recently.
i usualy have around 1 hour and 20 min worth of footage which i capture via firewire using showbiz from my lil sony dv handycam.

now heres the problem...
while im editing the footage, about 3/4 of the way through the footage...showbiz starts to 'drag'. The timeline kind-of sticks..and the preview cant keep up with the timeline and when u pause the movie the preview skips about 400 frames forward (making it very hard to cut at particular points).

It wouldn't be too bad, apart from that the 'drag' is sill present after i 'produce' the final movie as an mpeg2 and therefor shows up on the final burnt dvd as a 8 second pause and an awful 'buzzing' sound between some transitions.
This has happened every single time i have used showbiz with this amount of footage.

I have tryed re-installing showbiz. i have tryed using a differnt camera and differnt tapes. nothing seems to fix the problem.

i have a Pentium4 120gb hdd and 1gb ram so i doubt memory could be the cause...but i am open to suggestions...

If anyone has heard of this hapening with Showbiz or any tips i might have missed...please let me know

i do appoligise for this long long question...

thanx, loz