Help! Categories are not showing up

My site is at https://www.ShopTomlinsons.com. I just noticed a problem with my site after adding a new item to it - when I go to the main page and click on a specific category I just get a blank page and nothing else. This is the page that I'm trying to get to:

http://www.shoptomlinsons.com/index.php?main_page=index&cPath=3_86_87

That is the "Garden Flag" category under the parent category of Gifts and Home Decor and then under the Flags category under that. This is the only category that I'm having trouble with at the moment - can someone tell me why I might be getting this blank page?

I've recently had Image Handler 2 installed, as well as the COWOA mod. I would think that if it was either of those it would be IH2, but has anyone come across this before? Any help is greatly appreciated.

EDIT I also meant to tell you that if I go to the individual product pages they work fine - as far as I can tell it is this one category page only and that's it. The trouble is, this is the busiest page of my site (by a very long ways).

Thanks in advance.

Also, after doing some more research it appears that it has something to do with the word "garden". The reason why I say that is that if you do a search for garden on my site you'll get the same blank page. If you do a search for anything else you actually get something. Any idea what's going on?

This might be something similar:

http://www.zen-cart.com/forum/showthread.php?t=93772

Check out this link:

https://www.zen-cart.com/tutorials/index.php?article=82

Thanks for everyone's help. I narrowed it down to one particular item, which I've since disabled. This is a product that's been on my site for well over a year without any problems, so I'm not sure why it's causing problems now (this is a very recent problem because I visit this page often and just noticed the error). Anyways, it wasn't a "hot" item like the rest of them in the category are so I just disabled it and I'll deal with it later.

When (or if) I figure out what the actual problem was then I will post here again so others will be able to learn from my mistakes.

But once again, thanks so much to everyone who responded - I really appreciate it.

-andrew