Greetings fellow Open WRT users. First off let me tell you a funny story:
I've got a Linksys WRT54GL v11 which I just bought new today. After installing the kernel 2-4 firmware I tried to install the kernel 2-6 version but unfortunately it didn't work (Error 512) via the webinterface. So I just forcefully installed it using tftp .. I then started configuring and then something happened which I cannot explain until now: connection to the router got lost and I couldn't connect anymore (ping returned by ethernet adapter). So I cut off power and booted the router again and still the same thing. So I used the failsafe mode and connected via telnet to find out that I don't know much about the config files ... I also didn't really know what could have caused it. I just made some general internet settings but nothing that could have prevented me from accessing the router (I also tried wireless too).  Furthermore I had ping when booting the router so it was clear that there was a problem with the config. Because I couldn't figure out what the problem was I just thought that I would start from scratch and cleaned the nvram (although there was warning but my device wasn't mentioned and.. most times there are too many warnings wink). Unfortunately this didn't help at all in getting access... still the some picture.
Conclusively I used firstboot to delete settings which succeeded. So I could connect again and started changing some settings again (all was lost after all). But then the same thing happened again (definitely not related to configuring imo) and I basically repeated the same things again. Only problem this time was that it didn't work. Router just didn't boot anymore at all.. I only had flickering power light and all other connection lights glowing which is bricked. I switched on / off like 10 times to be sure that it's not something memory related and also tried taking power off for a longer period of time (1 min). But nothing helped and I got really frustrated big_smile So I just put it off power and switched it on again after 10min and surprisingly it booted normally ... So then I could use failsafe mode again.. guessing that all the problems came from first forcefully installing the kernel-2.6 driver I now used mtd to revert to kernel-2.4. After that I installed kernel-2.6 package again and that's basically my status at the moment.

tl dr: i fucked around with the router thinking i bricked it and got 2.6 kernel installed with difficulties wink

1. What could be the reasons for kernel-2.6 firmware getting the error while installing via web interface --> can i provide any more infos on this so you can help?
2. What could be the reason for the problem with just not being able to connect to the router (no ping after booting!)
3. How is it explainable that after waiting some time router went from bricked to normal again.. i thought nvram data wouldn't get lost if power is down?!
4. Setting up wifi using web interface does not work (no message or sth.) and using ssh and config (disable = 0) I still don't get signal with iwlist ..?
5. I didn't find the wiki article for wrt54gl very orderly in terms of finding what you are looking for --> imo lots of outdated stuff (kernel 2.4). Is there another guide, probably more comprehensive?

Thanks in advance for answers and even more thanks if you read everything.