Thanks for posting.
 
The reason you cannot tether may be due to the wpa_supplicant file.  This has been discussed on the forums for other tablets, including the Viewsonic G-Tablet I'm using now. (See review on main site.)
 
It seems that the wpa_supplicant files provided with Android do not permit connecting to adhoc networks.
 
You should be able to pull a corrected wpa_supplicant from one of the fixed firmwares, even if it is not an Augen Gentouch FW or even Android 2.1
 
No promises, since I no longer use my Gentouch, but if I think of it, and have time, I'll pull the file from a G-Tablet fw that supports adhoc, and put it in the Augen. I'll post again if it works.
 
 

OK, could someone please try this...
 
Warnings:
Messing up your wpa_suplicant.conf file will result in a device that can no longer connect to the network.
 
Root access and operations as root are required.  There is a possibility of rendering the device un-bootable, and thus unusable.  
 
Assumptions:  
1) We are Attempting to get an Augen Gentouch 78 online via a MiFi or similar "Portable hotspot" or a mobile phone in mobile hotspot mode.
 
2) The MiFi's network name is "my_mifi"  (use your actual network name in everything below).
 
3) You have access to the Gentouch via ADB.  (One-time configureation), and root access on the Gentouch.
 
Do:
On the Gentouch attempt to find the Access Point (AP) in Wi-Fi Settings.
 
If you see it, but cannot connect, try this.
 
Connect via adb.
 
Find the file /data/misc/wifi/wpa_supplicant.conf
 
copy it to the host PC for editing.
 
Look for an entry for your MiFi or ad-hoc network.  it will look something like:
 
Code:

	network={
	ssid="my_mifi"
	key_mgmt=NONE
	auth_alg=OPEN SHARED
	wep_key0=<key>
	priority=<some number here>
}
 

If you do not have an entry for the mobile AP, you can try creating one after the rest of the entries.  Start by cofpying the relevant section from a regular WiFi AP that you have successfully connected to in the past.  Use an unique and higher-numbered value for the priority value (i.e. 99).
 
add this to the specific entry:
 
mode=1
 
add the following to the top of the file _after_ the other initial lines (i.e. not in any specific network entry)
 
ap_scan=2
 
Save the file, and move it back to the Gentouch (obviously in the same location).  Make sure the permissions and ownership remain correct:  -rw-rw---- system   wifi      or possibily       -rw-rw---- wifi   wifi
 
 Try connecting to your Mobile AP again.
 
Credit:  User collindv from Slatedroid:
http://www.slatedroid.com/index.php?topic=5345.msg43689#msg43689
 
If this does not work, someone with the ability to make a wpa_supplicant binary (not just the .conf file) would have to build us one.