Same here. I don't think there's been a single post with someone confirming Unidays discount, but several indicating it doesn't work.
@maritrunks - may want to edit post title with a YMMV on the Unidays discount.
I was lucky to have a fellow RFD'r share a 10% code with me - I didn't ask where the code came from. I ordered Saturday, now I sit impatiently hitting F5 on the purolator tracking page, waiting for them to pick it up from dell. Also not sure if it's been mentioned yet, but rakuten is up to 5% at the moment for dell.ca.
Final edit: forgot to thank OP!