Cisco console connection

[ulty]

When consoled into my Cisco 2501, if I press the up arrow to retrieve past command, it will retrieve it, but then also send a few extra chars for some reason that are show on the screen as '^@' and result in a carriage return, executing the command. An example:

Walter>sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.0.2 10 00d0.58ac.ea15 ARPA Ethernet0
Internet 10.0.0.1 - 0050.736c.0000 ARPA Ethernet0
Internet 10.0.0.50 9 000f.f70f.3740 ARPA Ethernet0
(This is where I hit the up arrow, not that that is the only key I press)
Walter>sh arp^@
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.0.2 10 00d0.58ac.ea15 ARPA Ethernet0
Internet 10.0.0.1 - 0050.736c.0000 ARPA Ethernet0
Internet 10.0.0.50 9 000f.f70f.3740 ARPA Ethernet0
Walter>^@
Walter>^@

I'm using Hyperterm and hace tried various emulations, nothing seems to help.

[30111987]

i know nothing about cisco systems but a wild guess it something to do with ascii and unicode