XS1930 dropping ports

For a long time I've given up using the XS1930 because it would intermittently loose connectivity on a port.  I could see in the log the port(s) going up and down regularly.  Now I've got time to get back to it, I may have solved it (too soon to say for sure but it's looking better).  The solution seems to be to hard-write the port speed for each port, rather than leaving each at "auto".

I wondered if anyone else had this problem, or can offer any relevant suggestions?

Thanks all.