Cannot update anything in Leopard, Help Needed

I've had a MacBook that came pre-installed with Leopard since October of last year... I have never been able to successfully complete a software update...

In the past, the updates have downloaded successfully but would crash during the restart phase (the progress bar would stall on the first action, no matter what i was trying to install, and i would have to hold the power button to cancel the update...)...

There were somethings this affected but I have an Imac on Leopard that has updated everything just fine, so I have my iPhone, etc... plugged into that machine....

I had some extra time today, so i decided to reinstall Leopard to see if this problem would persist on my Macbook... the reinstall went fine (i Archived and Installed)...

When i searched for system updates, I had 14 programs that needed updating... now when i click update, it cannot even start to download the updates... i am getting a -3001 error message saying that it could not find download file and to check my internet connection.... I am connected and don't know what else the problem could be...


Thanks in advance for any help or advice!