The following information is contained in a post-em by Curt Hofemann, curt_hofemann@@yahoo.com:
What I have in mind is her (Katherine Keats-Rohan) article on Poppa, mother of William Longsword of Normandy, which appeared in The American Genealogist a few years back. Basically, she suggested that Juhel/Judicael Berenger was son of a Count Berenger, named by Dudo and William of Juminges, and that both this Count Berenger and William Longsword were maternal grandchildren of an Earlier Frankish Count Berenger. I have seen it speculated (i.e. by Guillotel) that Judicael Berenger's paternal grandfather might have been a son or grandson of King Erispoe, but there was little evidence with which to place him. [Ref: TAF 21 Nov 2000]
Note: I originally had Juhel as brother of Poppa, but the above reference to Katherine Keats-Rohan indicates that Juhel is probably nephew of Poppa, being son of another Berenger Count. The dates would certainly indicate that Juhel and William Longsword were in the same generation.