"Send Email" not working - too many customers?

[tobybailey]

Tools/Send Email has been working fine for years although I use it only occasionally.

 

Suddenly now the page is broken, loading only the left-hand menu with all the other stuff missing. (The html source just cuts off at the end of that menu too.) An identical page is working fine in a mock site and has not recently been changed. (Only recent changes to the site were SEO and validation). It acts the same with IE, Firefox and Chrome.

 

Could it be that with 19000 customers the drop-down list is just too large? Are we running in to some sort of cutoff either built in to oscommerce or a browser limitation?

 

I would be grateful for any ideas.

 

Toby