So, after complaining to IBM, they rang me back and promised to get back in touch by Friday. Last Friday. On Monday I rang them. On Tuesday someone else rang back and said that she'd chase up the person handling my complaint. On Wednesday, I rang them again. On Thursday, I rang them again and they rang back. To tell me that they'd failed to get in touch with my supplier, and so nothing had happened. Today they rang me back again, and spent half an hour telling me that while they weren't saying I was wrong about it being the Thinkpad refusing to work with the hardware rather than the other way around, I was wrong. And so they wouldn't take it back.
I find this interesting, because nestling at offset 28BF9 of the BIOS image is the string 80861043ff1080862551.
8086:1043 is the PCI vendor and device string of the Intel Pro/Wireless 2100B. 8086:2551 is the subsystem ID of the version sold as an IBM part. The standard Intel part is 8086:2486. Looking further, at offset 33AD8 there's 12603873. Coincidentally, 1260:3873 is the ID of the Lucent Orinoco chipset. At 28BEF, we find 168c1014 - oddly enough, the part number of the IBM 802.11a/b/g card. Every single wireless card that's available for the X40 (plus, for some odd reason, the Lucent orinoco) has its PCI ids in the BIOS. The BIOS is 631662 bytes long. The probability of any one 4 byte string containing one of those sequences is (1/256)^4, or 1/4294967296. Given 631662 bytes, there are 631658 positions that it could occur in, so we have 631658/4294967296 or somewhere in the region of 1/10000. The probability of finding 4 of these (there's actually another for the 802.11/b/g part at 28C0E, but the 4220 isn't immediately adjacent to the 8086, so it's less convincing) is therefore 4.7e-16. Or 0.47 except with 15 more 0s after the decimal point and before the 4.
I would tell IBM this, but they all buggered off early because it's Friday. So I have to wait until next week.
CEC, on the other hand, have been absolutely wonderful to me and I really can't overstate what super customer support they have. Shame about the website.
Further comment on how I feel about IBM will appear once I've worked out whether they're being malicious or incompetent. Capital letters are forecast.