For information I had the same bug.
I use Ubuntu Hardy. my wireless adapter is a ralink
0409.0 Network controller RaLink RT2561/RT61 rev B 802.11g
Linux AciD 22.214.171.124-bertox #3 SMP Sat Sep 27 163615 MUT 2008 i686 GNU/Linux
I used driver from kernel
description Ralink RT61 PCI & PCMCIA Wireless LAN driver.
vermagic 126.96.36.199-bertox SMP mod_unload 586
I had the No ProbeResp issue from generic kernel from ubuntu (2.6.24-16-generic)
So I compiled my kernel with the "IEEE80211_MONITORING_INTERVAL" option set to 1000 * HZ
I didn't have the No ProbeResp problem anymore. However, I was systematically disconnected. I mean the card seems to be connected to the AP, but no traffic at all.
After a lot of searches, I finally tried the Enhanced legacy drivers from serialmonkey
Result I've never been disconnected again !
I really don't know why kernel drivers seem to be broken (at least for me), nor what are the differences between the two drivers for end users, but if you have the No ProbeResp 'bug', you should try theses legacy drivers
Hope it will help someone