Roger I de Montgomery, Seigneur de Montgomery is Gommeri Ingvarsson, I's third great grandson.
Roger de Montgomery, I, Seigneur de Montgomery is the oldest profile i can immediately source ( http://fmg.ac/Projects/MedLands/NORMAN%20NOBILITY.htm#_Toc384196776 and http://en.wikipedia.org/wiki/Roger_de_Montgomery,_seigneur_of_Montg... ) his wikipedia page gives the names and dates of his parents but lists no sources so could be fictional. I haved moved Roger on the Tree from a very suspicious father (William de Monte Gomerii) to Hugues de Montgomery which matches what Wikipedia shows.
There is a note in the About of the next profile up the tree (Count Guillaume de Montgommery) which mentions a "...father was called Guillaume who descended from a Dane/Viking called Gormeric." This note seems to be from Anne Berge so i have left this profile as is for the moment.
The generation before this is Roger de Monte Gomerii (his name makes no sense to me - in a genealogical way), who's About seems to be a copy of Roger I's About so he is possibly mis-located? His father's name, William de Monte Gomerii, is also confused and possibly not based on anything substantial. Then we are back to Gorm / Gommer at the top of the tree with a note in the About from Anne "Family history says the name is from a noble Dane called Gommeri (Gorm?) and his residence near a mountain (Mont)."