I'm aware that there's an issue with the share daddy plugin part of JetPack interacting with MarketPress. I would like to request an update on the status of any possible fixes, as I would like to utilise the share daddy along with other jetpack features on my site. (I have marketpress enabled on a client site at lauragroomjewellery.co.uk)
Unfortunately at present I am unable to disable just the share daddy plugin as the jetpack admin screen won't load with a "white screen of death" i.e. no output and the error_log reporting premature end of script headers.