I support Quickbooks as a consultant/sysadmin for SMBs.
I have felt your pain. Which is why I wanted to respond when I noticed this part...
And it's compounded by the fact Windows XP doesn't route data over the ethernet as a priority over WiFi connection.
Check out the first set of instructions in http://support.microsoft.com/kb/894564 which should let you set a wired connection to a higher priority than a wireless.
In part, it's due to a severe shortage of computer security specialists and engineers with the skills and knowledge necessary to do battle against would-be adversaries.
Based on my own experience, I would argue that there is a severe shortage of computer security specialists and engineers with the skills and knowledge and desire to do battle against would-be adversaries. Whether it's a personal financial concern or a personal ethical concern, there are lots of great reasons for skilled and knowledgeable experts to seek employment elsewhere.
"Summit meetings tend to be like panda matings. The expectations are always high, and the results usually disappointing." -- Robert Orben