The hard disk counts all possible such / similar problems ever happened in its lifetime.
A re-format, complete erase or so will not clear these problems, as the counter still shows the original number.
The important is to prevent new problems. If you see increasing error counter, then it confirms that the situation is not stable: something (cables, connections, power issues, overclock or sometimes the chipset driver) can cause that the communication is not stable. This may lead to new and new errors. Even in a notebook, the connection can be problematic.
If the error counter does not change further, then you may any time clear the error-counter in Hard Disk Sentinel to acknowledge the problem and remove from the text description.
Then Hard Disk Sentinel will show only if there will be similar (or different) problem with the drive.
Please see www.hdsentinel.com/hard_disk_case_communication_error.php for more information about this issue.
Maybe you have issue with an other attribute (eg. 187) where you can clear the counter.
If you use Report menu -> Send test report to developer option, I can check the actual situation. It may give some thoughts what can caused the issue and what would be the best way to improve.