Transposon Theory Of Aging, some more support.

"As cells get older, prior studies have shown, tightly wound heterochromatin wrapping that typically imprisons transposons becomes looser, allowing them to slip out of their positions in chromosomes and move to new ones, disrupting normal cell function. Meanwhile, scientists have shown that potentially related interventions, such as restricting calories or manipulating certain genes, can demonstrably lengthen lifespans in laboratory animals."

http://www.science20.com/news_articles/a_transposon_theory_of_aging-180287

report at PNAS, but link not provided.