Navision error after I enter username and password

I get a message box with this message:

Internal error 2 in module 10.

Contact your dealer if you need assistance.
Then there's a link to view the error info which is in a file:
Information file prepared 12/10/05 09:12 UTC

Error Class=Internal Error
Program=Navision (03.70.02.19516)
Operating System=Windows XP (5.1.2600)
Total Physical memory=175MB
Used Virtual Memory=47MB
System Locale=1033
User Locale=1036
Global Language=1033
Code Pages=ANSI 1252 OEM 437

Server Connected=EFIN-NAV37SRV
Database Open=C:\Program Files\Microsoft Business Solutions-Navision\Database Server\database.fdb
Windows Authentication=No
Commit Cache=Yes
Database Cache(KB)=8000
Client/Server Version No=21

When i click don't send Navision starts ok. and when I try going to the object designer and click codeunit or anything else the error comes up again. When i close it the navision window is Grey. I can click on menu buttons but it just thinks and nothing happens..
Does anyone know How to fix that. Because I have important code in one of the code units i really need.