Viper and pixmap background conflict

Hi, I find the pixmap background picture really cool. I now do my editing over a beautiful mountain landscape. The only problem is that this has a bizarre interaction with Viper. Backspacing in insert mode is very, very slow and it lags behind my typing. The same thing applies to holding down return. It seems to be redrawing the whole screen whenever I press return or backspace in insert mode. I have narrowed this down to cursor color. Viper changes the color of the cursor to green when in insert mode. If I turn off this handy feature, return and backspace in insert mode work at a normal speed. It seems like Viper changes this a lot, as backward-delete-char resets the cursor color to the default (???? is this a bug?). So, by this theory, Viper would be changing the cursor color every time I press backspace or return in insert mode, and for some reason changing the cursor color using (modify-frame-parameters) would redraw the screen. That would explain why these keys lag behind me. I'm wondering who's bug this is and how I can help to fix it. This is XEmacs 21.1.12 on X-Windows and the Viper that comes with it. And please, no Vi vs. Emacs flames. Thanks, Aaron Lehmann