Hi Alan,
Please share a few more details? (and at least the Xerox printer is on Eth and not Wireless)
1) Is the 7372 used in Solo/Standalone mode (what version), or managed by a Ruckus controller (ZD/SZ, and what version)?
2) What is the version of Cisco SG300, and is it their latest?
3) Is the printer connected to the same switch as the AP, or across the network (how many hops, what intermediate equip)?
Two troubleshooting scenarios come to mind - is this an AP/wireless issue, or the local LAN/VLAN 1 wired network perhaps?
How to Test? Can one of the users reporting no problems now be connected to the second Eth port of the 7372?
Can you evaluate that user's ping/printer gui access when Wifi users say they have problems? If both are broken,
at the same time, we need to look at the AP, it might have some memory utilization issues, especially if this is all on
one switch (on latest Cisco code). If we need to upgrade your AP/controller, we should do that too.