Unable to upload images

I've been using the latest version of ZenCart since early March, and haven't had a problem uploading product images before.

However starting yesterday, when I tried to upload an image for a product it spent ages loading, but when it finally loaded the preview page, the no image message was displayed.

I haven't made any changes to settings so I really don't know why it's doing this. Has this happened to anyone else before?

Thanks in advance!

Report back any error logs in this folder please: > root directory/ cache

How do I go about doing that? I'm afraid I don't know much about the program - my web designer just had a heart attack, and now I don't really know what I'm doing...

Sorry to hear about your web designer, but now it is time to read the "Tutorials" in the link above about the procedures and tools of Zen Cart..> click on the link on the top right hand side of this page called Tutorials/FAQ.. Notice at the bottom the Tutorial Headings

Ok found this:

[03-May-2011 00:47:35] PHP Warning: reset() [<a href='function.reset'>function.reset</a>]: Passed variable is not an array or object in C:\CustomerData\webspaces\webspace_00253025\webapps\SiteApp124444\htdocs\admin\includes\classes\object_info.php on line 29

[03-May-2011 00:47:35] PHP Warning: Variable passed to each() is not an array or object in C:\CustomerData\webspaces\webspace_00253025\webapps\SiteApp124444\htdocs\admin\includes\classes\object_info.php on line 30

Is that to do with the image upload situation?

Also found this:

[13-Apr-2011 13:22:17] PHP Warning: Variable passed to each() is not an array or object in C:\CustomerData\webspaces\webspace_00253025\webapps\SiteApp124444\htdocs\includes\classes\db\mysql\query_factory.php on line 127