There is allready a small mod from Chirmaya which will fix this (but I´ve not tested it yet):
http://chirmaya.impulsedriven.net/article/336701/REL_Unofficial_Beta_2A_UI_Quickfix_v2
Some informations about this mod:
Changes:
- Rounds the roll-over HP values to non-decimal numbers.
- Allows you to tab back and forth from the username and password fields in the Log In screen, although there is a small graphical bug.
- Allows you to tab back and forth from the gamename and password fields in the Host Game screen, although there is a small graphical bug.
*Note: This is a User-Interface mod, so it doesn't require anyone else to have it installed.