We have had a serious problem getting 1242 access points and mounting plates to fit together.
The only workaround we have been able to come up with is to slightly re-bend each tab on the mounting plate so that it will fit into the slot.
I do not know if we simply had a "bad" batch of APs or if this is going to be a chronic problem.
I believe that the approx. APs manufacture date is in the Spring 2006 timeframe.
Has anyone else experienced this?
Cisco: if you are monitoring this thread, are you aware of this and, more importantly, has this problem been resolved?
This is a known issue, and the good news is that there is a free upgrade program in place. Have a look :)
Field Notice: FN - 62349 - Aironet 1240 AG Access Point Mounting Bracket
From this doc;
Hope this helps! Take care.