I think the supplier is correct.
Also following features are not supported by these switches
# Non-IP protocol ACLs
# Bridge-group ACLs
# IP accounting
# ACL support on the outbound direction
# Inbound and outbound rate limiting (except with Quality of Service [QoS] ACLs)
# IP packets that have a header length of less than 5 bytes
# Reflexive ACLs
# Dynamic ACLs (except for certain specialized dynamic ACLs used by the switch clustering feature)
# Internet Control Message Protocol (ICMP)-based filtering
# Interior Gateway Routing Protocol (IGRP)-based filtering
Following link may help you
http://www.cisco.com/en/US/products/hw/switches/ps628/products_configuration_guide_chapter09186a00801cde58.html