CMS Made Simple Forums

I have a client who builds very large slideshows for his website. They are zipped and he has been uploading them via the filemanager without too many problems under 30 Meg in size. He has been having a horrendous time with a couple of the shows that are 40 plus Megs. I have no idea how and if it is possible to change a setting somewhere. I am using version CMSMS 1.2.5

thanks for the help