110
Just a quick logical check
considering that XOOPS uses MD5 enycrption, just encrypt your orignal password using MD5 enycrpting tools and check if it looks the same as its in DB. (just a guess that XOOPS uses MD5, confirm it from devs). If its the same than you can be happy that you DB is ok. Now all that you need is resinstallation of 2.0.7.3 or reverating back to you old backup. But if db has gone bad then its a mess for you...
Best of Luck