Does this relate to your problem?
I am having a problem with IM email. I have been receiving Blank emails. Has nothing in the From line or the Subject line. I do not open the window on them as I am afraid they might be a virus.

might be due to an email in her inbox that is stuck (ie: when she finds it it will stay in her inbox no matter how hard she tries to delete it)I've had this happen to me a couple of times and of course have the fix if this is the problem 
 
First she needs to make a new folder and move ALL of her emails to this folder, my guess is that one or more of the legit mails she has will not move (if not it is probably evil emails but if so this is what is making her emails download blank)
 
then she will need to find her message store file...mine is here for example
 
C:\Documents and Settings\Deann\Local Settings\Application Data\IM\Identities\{1327BC51-7516-410D-ABD5-590B7BABBD43}\Message Store
 
and delete the inbox.imm and inbox.imh files
 
IM will rebuild the file and she should be fine