Gibberish in Apache Error Log

I have been running apache on my win98 machine with mod_dav for about a week now.  (Console start-up message:
Apache/1.3.22/(Win32) Dav/1.0.3-dev running...)

When I got up this morning my machine was completely locked and needed to be hard rebooted.  I checked the apache access and error logs and found puzzling evidence.

The access log ends with a standard set of entries looking for an IIS vulnerability (...cmd.exe?/c+dir etc...) then a line with maybe 1000 high ascii boxes that ends with @þÿÿÿÿÿÿÿÿÿ.  The error log is completely full of junk:  30 of so lines of things like:¬BQh8B@, then a whole set of attempted commands mixed with more high ascii:

RegReadWriteString (for identity of the package) returned false or failed
GetSecurityAdmin failed
GetSecurityAdmin passed
GetMtsAppIdentity failed
GetMtsAppIdentity passed
pCatObject->get_Value (for changeable on a package) failed
**Error** Changeable did not come back as a BSTR
Setting Property Failed
Setting Property Failed
Setting Property Failed
SaveChanges (on packages after setting the identity and password) failed
Setting Property Failed
SaveChanges (on packages after setting changeable to NO) failed
pPkgCollection->GetCollection for RoleCollection failed
WalkRolesMigratingUsers failed
pIRNPack->MoveToParentKeyOfKey failed (SERIOUS ERROR 1)

I can't any mention of any of these errors anywhere - not in the apache docs, web_dav docs, even google brings back 0 hits.

Any one have any clues?

thanks....