Guess what! The problem is solved!
But not until I practically deleted the whole site and started all over, restored the profile related database tables for a few times, messed with xoops_newblock table for some odd reason of c_type structure column missing (something obviously totally unrelated). In the end it turned out that Gravies was right and that I just didn't pick up a message quite well and wondered around instead.
What I mean is this. What finally solved the problem was checking the last entries in the xoops_user_profile module. As it appears, every times me or anyone else tried to register it created a yet another pretty much empty entry with the "posts" column filled with "-1". So, even if I restored the xoops_user_profile_field table, and any other related table for that matter as well as deleted the c_templates files it didn't solve the problem as those trash entries went in the way somehow.
Deleting them solved the problem.
I wasted quite alot of time rebuilding my site from scratch (from db backup of course) and I should have probably lost alot less of time over this if I only figured to look into the
end of the xoops_user_profiles table. Gravies mentioned something like that on IRC, but I thought he was talking about deleting those users from the XOOPS user admin area (with the status of "-1"). Well, I obviously misread him.
All in all, I am very happy to have this problem solved and that I can again welcome new users to my site. And the time I lost rebuilding the site wasn't really for nothing. The "recent blog entries" block that cause 500 internal server error was solved as well and I took the chance while I was at rebuilding to port my content from buggy wfsections 2.01 module to awesome new smartsection 1.1 beta for 2.2. It works like a charm.
Anyway, before I stop ranting here is one error I am still getting in MySQL debug when deleting users (which could possibly cause some trouble and should thus be killed ASAP):
Quote:
Queries module
SELECT * FROM xoops_users u, xoops_user_profile p WHERE u.uid = p.profileid AND uid = '478' LIMIT 0, 1
( 0.006545)
DELETE FROM xoops_users WHERE uid = 478
( 0.076539)
DELETE FROM xoops_user_profile WHERE profileid =
Error number: 1064
Error message: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
( 0.000143)
DELETE FROM xoops_groups_users_link WHERE uid = '478'
( 0.054166)
As you can see it's in "Queries module" section of the debug window and the error is in bold text.
According to the error it is in MySQL syntax and causes the inability to delete an user entry from xoops_user_profile table.
That is why I had to manually delete those bad registration profiles from it to resolve the above problem.
Extended profiles module of both 2.2.2 and 2.2.3 XOOPS is obviously still buggy. I hope the next release is finally "ironed out".
Thank you
Daniel