The following should work fine with 2.49 - so update if 2.48 fails.
Proceed as follows:
load the files into mp3tag.
Press F3 to display the filter entry box at the bottom if is not already there.
Enter the following line as filter (including the quotation marks):
"$if($eql(%artist%,%album%),1,0)" IS 1
this filters all the files where artist and album have the same contents.
Select all tracks in the files list (press CTRL-A)
Turn to the tag panel on the left and navigate to the tag that you want to delete and select "delete" (or "remove" I do not know how it shows up in the English version) from the drop down list (which now shows "keep") "delete" (or "remove" I do not know how it shows up in the English version).
Press Ctrl-S to save the changes.
Have a look at the FAQs - this is one of the really frequently asked questions: /t/967/1
As a format string any combination of literals and contents of tag-variables is allowed. Tag-variables are enclosed by the % character, e.g. %title%
f you want to append TITLE by "Best stuff", use the string
Best stuff - %title%
And another thing: if you have further questions please start a new thread as it would be easier to judge from the topic what the problem is - also, if others search the forum, it makes it simpler to rule out the non-hits...