Welcome to the forums Floody.
Assuming that you are capturing via that firewire card then everything will be resolved.
First of all ditch that crappy footage that you captured.
Then defrag your hard disk.
In ULEAD make sure that you are using the defult capture template for DV-AVI. If you have a seconf hard drive then capture your footage to there, and set your temp files to the second hard drive. (File > Preferences > General TAB: Working Folder and File > Preferences > Preview TAB : Uncheck number 1 and change number 2 to a folder on your second hard drive.
Then capture and edit.
I am off to Rome for a few days (wo is me) but I will check back on Sunday to see how you got on.
COMPAQ something or other with 500Gb Boot Disk, 1Tb external Firewire Disk, 4Gb Memory and a super duper sound card, 19" TFT Monitor etc etc etc
Sony TRV33e : Sony TRV310e : Canon XM2
Sony Vegas Studio editions to v11
Remember, there is always more to learn than there is to teach.