Sorry if this seems random but has the wallet issue been solved where you were unable to send large amounts of coins? I had an issue when I used quark some time ago that wouldnt let me send large amounts and I believe this was a known issue. I had to split the transaction into ever decreasing amounts.
Have you downloaded the newest version?
www.reddit.com/r/quarkcoin at the left upper side are the most updated quark wallet. The newest version is 0.8.3.20