I've had this problem too a couple of times. The only thing that was wrong was bad ident response from client. Since ioFTPD by default caches idents for 1800 seconds (30 minutes), for faster login, one bad ident response from clients ident-daemon makes it impossible for user to login with correct ident@ip for 30 mins. By bad ident response I mean no response. That makes user's ident@ip to *@ip and not ident@ip. When the user then tries to login with ident@ip ioFTPD still thinks that user has *@ip. That is the problem. You can probably see entries in your Error.log that says the user's host did not match the ident@ip added for that user.
And also.. ident is for *nix operating systems. Windows OS can only "fake" ident response. That response will never be 100% the same as for *nix. And doesn't follow the RFC standard, it simply can't. So I've been told by Dark0n3 anyways.
I've been experiencing problems with my ident in windows. I've tried several different solutions, the identd in mIRC, and the one in FlashFXP and a couple of stand-alone ident daemons for win32. Sometimes, just sometimes, my ident daemon's response to server's ident request does not reach the server. I really don't know why.
So what is the solution?
First the standard stuff. If you have a firewall, make sure port 113 is open. Since ident seems to work for you (but not always) I guess the port is not the problem.
Second you could try decreasing the time that ioFTPD caches ident. Under [Network] in your ioFTPD.ini you can find these settings (among others):
Code:
Ident_Timeout = 15
Identity_Cache_Validity = 1800
Maybe ident needs a little more time before ioFTPD considers it timed out. Try increasing Ident_Timeout by a couple of seconds and see if it helps.
AND..
Set the Identity_Cache_Validity to 0 (to disable ident cache) or just decrease the value to let's say 300 seconds which is 5 minutes. That will make login faster for users who want to connect with a second session after first login, or makes login faster if that user forgot something after disconnecting and has to log in again to grab this or that file.. within 5 minutes after first login that is.
When those 5 minutes has passed ioFTPD will wait for "real" ident response for that user.
Hope it helps.
/Zer0Racer