Easy Populate like things kept SIMPLE... as does php and MySQL. The minute you start using "special characters" in the content (data), you risk corrupting it, because some characters are used in the programming for various purposes.
Back and forward slashes, single quotes (even as apostrophes), % signs, @ signs, and many others, can wreak havoc in the data.
I have seen many people give their images very elaborate names - some using square brackets, periods, slashes, aplostrophes, etc - or a convoluted combination of all of these. And the result is usually a confused mess in Easy Populate.
Even in the product description text, some characters give real problems - such as single quote marks and apostrophes. I try to use HTML character codes for these, so instead of saying "it's the best product on earth", I would use the HTML character code for the apostrophe (it& # 3 9 ;s) - no spaces of course... I put spaces here to prevent your browser rendering it as an apostrophe!
I deal with a lot of this in my WIKI
http://www.zen-cart.com/wiki/index.php/Easy_Populate
Additionally, if your product descriptions are long - or contain formatted line breaks - a program like Excel can TRUNCATE the text. Many people write up their product data in programs like MSWord and then use COPY and PASTE to get the text into the spreadhseet. This will copy MS formatting too - which is an absolute NO-NO.
So when I populate the v_products_description datasets I MAKE SURE not to have formatted line breaks and replace all these with <br /> tags. I remove ALL other formatting - or at least replace it with good, clean html tags.
Read my WIKI for additional advice.