Hi John_Dean,
The more you submit, the more time the spiders take to recrawl your site, thus making the major search engine difficult to rank you accordingly..
up to 5 times is all right.
Dont bother submitting your site to search engines. Its best if they find you from backlinks on other sites. You wont get better/ any PR from submitting your site to SE, PR comes from other sites linked to you and the value of there PR and there standing according to google.