Error: pin 2-6

I have the arduino IDE set up, and have successfully used it to program one duemilanova. I have a second duemilanova (for the mark 2 of my project, mark 1 being in field test), but what I get from it via the serial monitor is error: pin 2-6 (and occasionally 2-5 and 2-8. I have nothing connected to the board beside the USB port. The software I attempted to upload was the stuff which I uploaded for the other duemilanova. I have also attempted to load example sketches, like analogInput from dojo dave.

The physical indications - power led on, rx led flashes briefly, tx led flashes in time with the error messages.

Also the IDE locks up during the "upload". The lock-up can be fixed by pulling the usb cable out, or by two three hits of the reset button on the arduino. OS is XP sp3.

Points I observe. The IDE does not give me a board choice of duemilanova. I use diecimila. I think that was the choice I had before. This duemilanova was bought some time after the previous (working) one. I have moved disks around on this PC, and, on inserting the USB cable, I had to find the drivers again, but I did, in the expected place. The port number of the USB moved from 6 to 7, but I did have a disk drive connected on a USB port, and it was not present before.

The project is a guide device for a blind man. I hope this makes it worthy of useful advice.

Thanks in advance

but what I get from it via the serial monitor is error: pin 2-6 (and occasionally 2-5 and 2-8. I have nothing connected to the board beside the USB port

This doesn't make any sense.

The IDE does not give me a board choice of duemilanova. I use diecimila.

What version of the IDE are you running?

IDE version, as far as I can determine, 0012 alpha.

All good. Updated IDE to 0022. Bought a new board (nano), so elected Nano. Works fine Tried previous board, selecting Duemilanove with atmega328 - loads fine. So I suspect the original board I had, where everything worked, was a Duemilanove with atmega 128, whereas, the board I had trouble with was the 328.

Thanks for your help.