I'm still not sure what's going on, but from your screen shot - I can presume/surmise this perhaps;
* it's a Domain Name Server (192.168.1.254:DNS)...are you using a Router as well ? - with 1 PC, you can easily disable many addresses / close off any other subnets entirely, use it's built-in firewall (if it has SPI capabilities),

In ZA's control panel - click Security Tab, then Advanced - post screenie

* the ^X^A type letters may be/are indicative of CMD (Command prompt) type CTRL key characters - try Start | Run CMD (a command prompt window opens) -- now type CTRL+X and you'll see what I mean -- what exactly that tells us ...? I'm not sure yet.

* the mathematical characters may be indicative of an application that normally has access and uses those types of fonts (any CAD, or 3D drawing app, etc)

* it doesn't seem necesary for you to have/use xxx.xxx.1.254 for anything, except perhaps your DSL(?) Modem may have that address assigned automatically -- many Cable/DSL modems use xxx.xxx.1.100 or .1.101 or other similar for their reserved base address, for accessing their configuration options and status (web interface to config)
(type http://192.168.1.100 into your Address Bar)

and if your Router is acting as the DHCP Server for your 1 PC LAN, then it's obtaining the DNS's from your ISP

Start | Run CMD then Netstat -a and /or ipconfig /all for some general netwrk connections info (forgive me, but you'll need to look up specific 2K/XP commands, as I'm not using those OSes)

PLZ - empty you entire JAVA cache and disable it
Control Panel | Java Plug-in | Cache Tab
click Clear -- then Untick "Enable Cache"

running CrapCleaner www.ccleaner.com will delete all those stupid win caches / history / index.dat / recent / cookies nonsense

post back and keep us informed after this, and let us know what steps you've taken and naturally if it's still occuring