I am well over my 125mb limit on a shared hosting plan, but the real issue is that I do not know what is casing the Datatbase to swell to over 5gb.  I cannot do simple things like delete portals (I only have 10 parent and child portals on one DNN install) and the site is not displaying properly.  My Shedule History log is 391mb and the event log was 35mb before I cleared it.  Here is a sample of the 70+ General Execptions that I am getting when I tried to delete a portal:

  6/19/2008 5:13:27 PM   General Exception       AssemblyVersion: -1; PortalID: -1; PortalName ... AssemblyVersion: -1
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL:
AbsoluteURL:
AbsoluteURLReferrer:
UserAgent:
DefaultDataProvider:
ExceptionGUID:
InnerException: Could not load type ''.
FileName:
FileLineNumber: -1
FileColumnNumber: -1
Method:
StackTrace:
Message: System.Web.HttpException: Could not load type ''. ---> System.ArgumentException: String cannot have zero length. at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase) at System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) --- End of inner exception stack trace --- at System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) at DotNetNuke.Framework.Reflection.CreateType(String TypeName, String CacheKey, Boolean UseCache, Boolean IgnoreErrors)
Source:
Server Name: EIOSWWW2

Sorry, I should have noted that the transaction log was not too large, and I cleared the Event Log.  Only the Schedule History seemed inordinately large.  I have no way of viewing the Tables, and the host didn't know exactly what to look for in the database that would be the obvious culprit. 

First the probable fix for your issue (errors), Mitchel Sellers blogged about this sometime back, you can find his blog on this topic here.

Second, your DB size: you need to get your host to setup (if you don't have access to SQL in your hosted control panel) a backup with truncate_only plan (daily/weekly) for your DB transaction log file. This will stop the file from growing out of control.