old version of oscommerse not compatible with php5

Hi there.

Im not sure if these questions really relate to cPanel but....

since my hosting provider upgraded to php/mysql 5 my oscommerce site has stopped working.

Does anyone have any sugguestions of what steps i can take to rectify this problem. Is there simply a line of code i can add somewhere?


One more question....

One of the zip files (products) on my other site (zen cart) wont download. It is no larger than the other zip files.
when i click on the download link after making a test purchase i get a 404 page not found!

I think it has something to do with the time the server takes to run a script on the file. I am using a mac and the only thing i can think of is that the hidden files created by mac are slowing down the time it takes for the server to execute this script. Thus getting a 404 msg.

Is there a quick and easy way to view/hide/delete these hidden files?

However my theory might be a load of rubish as im not very knowledgable on this sort of thing.

any sugguestions would be great.

Thanks.