How might I reduce the percentage of rejected shares using an Avalon 741 with NiceHash? I have an Avalon741 running on NiceHash with CGminer and I'm new to mining. The command I'm running is as follows:

sudo ./cgminer -o stratum+tcp://sha256.eu.nicehash.com:3334 -u &lt;address&gt; -p d=4096


When I run with this, I end up getting usually between 25% and 50% of shares rejected. Why is this? How can I improve the situation and contribute more effectively?

Here are some representative CGminer run statistics:

[2017-06-07 12:57:08.511] Started at [2017-06-07 02:20:49.716]                    
[2017-06-07 12:57:08.511] Pool: stratum+tcp://sha256.eu.nicehash.com:3334                    
[2017-06-07 12:57:08.511] Runtime: 10 hrs : 36 mins : 18 secs                    
[2017-06-07 12:57:08.511] Average hashrate: 5032956.9 Mhash/s                    
[2017-06-07 12:57:08.511] Solved blocks: 0                    
[2017-06-07 12:57:08.512] Best share difficulty: 140M                    
[2017-06-07 12:57:08.512] Share submissions: 7258                    
[2017-06-07 12:57:08.512] Accepted shares: 5335                    
[2017-06-07 12:57:08.512] Rejected shares: 1923                    
[2017-06-07 12:57:08.512] Accepted difficulty shares: 44435456                    
[2017-06-07 12:57:08.512] Rejected difficulty shares: 15138844                    
[2017-06-07 12:57:08.512] Reject ratio: 26.5%                    
[2017-06-07 12:57:08.512] Hardware errors: 11355                    
[2017-06-07 12:57:08.512] Utility (accepted shares / min): 8.39/min                    
[2017-06-07 12:57:08.512] Work Utility (diff1 shares solved / min): 94093.46/min

[2017-06-07 12:57:08.512] Stale submissions discarded due to new blocks: 7                    
[2017-06-07 12:57:08.513] Unable to get work from server occasions: 12                    
[2017-06-07 12:57:08.513] Work items generated locally: 274339                    
[2017-06-07 12:57:08.513] Submitting work remotely delay occasions: 6                    
[2017-06-07 12:57:08.513] New blocks detected on network: 1960

[2017-06-07 12:57:08.513] Summary of per device statistics:

[2017-06-07 12:57:08.513] AV7 0 (5s):32.99G (avg):5.032Th/s | A:44435456 R:15138844 HW:11355 WU                    
[2017-06-07 12:57:08.513]
If you live in the U.S. you need to connect to the US server.

stratum+tcp://sha256.usa.nicehash.com:3334

NOT

stratum+tcp://sha256.eu.nicehash.com:3334