Replaced all !'s with ?'s in url references. Turns out that R5 allowed for either ? or ! to be used as a query string separator but in ND6, ! is not allowed unless a special ini variable is set. Since ? will work everywhere I elected to stick to this for now (was getting way to many emails on this problem!)
Added support to the &RestrictToCategory optional argument. Lotus still does not support using the other optional arguments such as &Start, &StartKey, &ResortAscending, &ResortDescending when used in conjunction with the &RestrictToCategory argument, therefore these actions will not work when also doing a RestrictToCategory. Will need to disable these features when a view is presented this way. Also, please note that for the time being you will need to use the &RestrictToCategory argument exactly as it is written. I will add support later on for a developer to choose an alternative name to the argument.