This coin has more problems with the connections than any other coin. I've never seen anything like this.
I've used like 20 other wallets and coins, and Quarkcoin is the only coin I've ever used that won't connect. All the other coins work perfectly.
Don't tell me to addnode the IP's. It doesn't matter if you addnode all the IP's, or try everything. It still doesn't work. And why did you remove UPnP support?
You've messed up something with the networking code that none of the other coins have messed up.
I can't get Quark to work on 3 out of 4 of my computers, and I gave up after trying for hours.
If it doesn't sync blocks, or speed was too low, one block at a time. Let's try remove quarkcoin conf folder, re-make conf file, then run from the start. It worked for me.