Just saw the new big update. So I need a PC connection.
Ovi, PC Suite and Nokia Software updater don't recognize my N900. not on my PC and not on my laptop.
What now?

Unable to use FOTA (Firmware-Over-The-Air)? Application manager should offer you the update when it comes available for your timezone.

For me this is the preferred way as Nokia Ovi Suite and Pc Suite do not work on my laptop (neither support Linux or Solaris).

yes It showed up in my app manager, but when I tried to install it I got a message that I should connect it to my PC???

Have you read this thread?
http://talk.maemo.org/showthread.php...6&goto=newpost

Yeah, I know, it's huge. There might be some help. Have you installed previous minor update 44? You can not update to 51 before you have 44 installed.

Also, are you using the latest versions of Ovi or PC suite?

Check also, that the phone is in PC-suite mode when you connect it to PC.

I have used PC-suite on windows laptop and it did recognize N900, but only when I used specific USB-port for connecting the phone. If the phone was in any other port, it was not recognized. So maybe you can try to connect to another USB-port. Also, do not use an USB-hub in between your phone and PC if you have one.

Did all that, just haven't tried switching USB ports.

I just don't know why I can't update OTA, while, if I understand correctly, others can???

Because some of the -devel apps (or their dependencies) you've installed conflict with the update. If you uninstall them then you'll be able to update OTA.