Losing Connectivity to CC

System

One of our user loses connectivity to Content Center after about an hour of non-stop generating files or previewing or any
activity within TeamSite FormsPublisher. After reconnecting, it starts happening very frequently and sometimes user cannot work at all.
When user switches to another machine, everything seems to be ok there.

Client machine details: OS - Windows 2000, SP4 & IE - 5.1, SP 1

TS Server Details: Windows 2000, SP4. TS 6.0

Any help would be appreciated.