How to reset hotspot key?

Question

I am new to Ubuntu.

I wanted to create a wifi hotspot from my wired connected laptop. I followed these instructions

http://www.howtogeek.com/116409/how-to-turn-your-ubuntu-laptop-into-a-wireless-access-point/

which worked quite well.

Ubuntu assigned a default wep key for this hotspot. I used it to connect another laptop I have and everything was fine. However, I decided to change the default key and its type from wep to wpa. I did this in the "wireless security" tab, pressed save and exited. I then tried once again to change the key and I was welcomed with:

"password or encryption keys are required to access the wireless network" 

which was expected. What was unexpected was the fact that it does not let me through using the key I set just before. Is it expecting the default key? Why if I had changed it (and saved it)? Now I get three or four windows with the same message every time I try to access.

How can I reset this key? Why is it behaving this way?

I use Ubuntu 12.10 on an Asus laptop.

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00:00.0 Host bridge [0600]: Intel Corporation Core Processor DRAM Controller [8086:0044] (rev 18)
00:01.0 PCI bridge [0604]: Intel Corporation Core Processor PCI Express x16 Root Port [8086:0045] (rev 18)
00:16.0 Communication controller [0780]: Intel Corporation 5 Series/3400 Series Chipset HECI Controller [8086:3b64] (rev 06)
00:1a.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b3c] (rev 06)
00:1b.0 Audio device [0403]: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio [8086:3b56] (rev 06)
00:1c.0 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 [8086:3b42] (rev 06)
00:1c.1 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 [8086:3b44] (rev 06)
00:1c.2 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 [8086:3b46] (rev 06)
00:1c.5 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 6 [8086:3b4c] (rev 06)
00:1d.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b34] (rev 06)
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev a6)
00:1f.0 ISA bridge [0601]: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller [8086:3b09] (rev 06)
00:1f.2 SATA controller [0106]: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller [8086:3b29] (rev 06)
00:1f.3 SMBus [0c05]: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller [8086:3b30] (rev 06)
00:1f.6 Signal processing controller [1180]: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem [8086:3b32] (rev 06)
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI Robson CE [AMD Radeon HD 6300 Series] [1002:68e4]
01:00.1 Audio device [0403]: Advanced Micro Devices [AMD] nee ATI Cedar HDMI Audio [Radeon HD 5400/6300 Series] [1002:aa68]
03:00.0 Network controller [0280]: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) [168c:002b] (rev 01)
05:00.0 System peripheral [0880]: JMicron Technology Corp. SD/MMC Host Controller [197b:2382] (rev 80)
05:00.2 SD Host controller [0805]: JMicron Technology Corp. Standard SD Host Controller [197b:2381] (rev 80)
05:00.3 System peripheral [0880]: JMicron Technology Corp. MS Host Controller [197b:2383] (rev 80)
05:00.4 System peripheral [0880]: JMicron Technology Corp. xD Host Controller [197b:2384] (rev 80)
05:00.5 Ethernet controller [0200]: JMicron Technology Corp. JMC250 PCI Express Gigabit Ethernet Controller [197b:0250] (rev 03)
ff:00.0 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers [8086:2c62] (rev 05)
ff:00.1 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture System Address Decoder [8086:2d01] (rev 05)
ff:02.0 Host bridge [0600]: Intel Corporation Core Processor QPI Link 0 [8086:2d10] (rev 05)
ff:02.1 Host bridge [0600]: Intel Corporation Core Processor QPI Physical 0 [8086:2d11] (rev 05)
ff:02.2 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d12] (rev 05)
ff:02.3 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d13] (rev 05)

Answer 1

I wasn't able to reset the hotspot key but I was able to reset the network manager to its default using http://ubuntuforums.org/showthread.php?t=1604124.

This deleted the (ad-hoc) hotspot that was giving problems. Anyway, after creating a new hotspot (and writing down the default key) I disconnected. Once I tried to reconnect, I was asked for authentication:

"password or encryption keys are required to access the wireless network"

I put in the default key and I still wasn't able to reconnect.

I'm guessing the ad-hoc characteristic is precisely that you use it only once. Afterwards, if you need another hotspot, then you create another one (which gives a new key, of course). Plainly, these hotspots are not re-usable. Is this correct? Can somebody clarify please.

Thank you.