Unable To Insert New Product!!

I was wondering if anyone could help me figure out why I am unable to insert new product after upgrading to 1.5.3? Before upgrading I was able to upload new product with no problems...I have been using ZenCart since 2008 and this is the first time that this has happened to me. My ZenCart that I was on before upgrading 1.5.1...I upgraded via FTP.

The problem started the next day when I decided to add a product to my site. I went in as usual to add new product, previewed before inserting...as soon as hitting the insert button no new product was uploaded....

Thank you in advance to anyone that can help with this situation!!

Any logs in your /cache and/or /logs folders? What plugins do you have installed? Any that "muck with" /YOUR_ADMIN/categories.php?

Thank you for responding…

I have not plug ins installed…Where are the logs located in ZC...