window freezing/taskbar hiding problem... DHCP error involved?

Hello. When I found dial-a-fix (downloaded & tried latest version, v0.60.0.24), I was hoping it would solve a long-standing problem I've had. Using XP w/SP2 & all the latest updates. What happens is occasionally (3-5 times a day) at no apparent timing interaction with any other programs (sometimes even happens at boot with no programs opened) the taskbar hides, and any open windows will not respond to attempts to click on anything (like minimize, links, etc.) until I either do ctrl-alt-del to bring up the taskbar (and then just close it) or do alt-tab and bring up a window, and then viola, all is fine again... for awhile. I do not recall exactly when this started (to see if it started when a new program was installed or something), but has been going on for weeks.

I have tried everything [short of a clean reinstall of XP] including complete virus & spyware scans with good detection programs, making sure no rogue programs are running in the background (or at startup), system restores, etc., etc., etc.

Don't know if it related or not, but there is one entry in the windows error log (the one you get to thru help & support) that occurs each and every day, the exact same error listed about 2-3 times each and every day. The error is

The IP address lease xxxxxxxx for the Network Card with network address 000AE6FD421E has been denied by the DHCP server xxxxxxxx (The DHCP Server sent a DHCPNACK message).

(yes, ther were numbers there instead of the x's) Could this be related? My internet connection (DSL via a regular DSL modem, no router, no wireless) has always been fine, no problems.

I'm kinda clueless what exactly might help using dial-a-fix; all I've tried so far is what sounded similar on the 'dial-a-fix tips page, the section where it talked about DCOM errors. I tried there what was recommended, but no help.

Anyone's help would be greatly appreciated!