Hello! Attached quick patch fixes the false negatives. Regarding the false positve, it's due to iceweasel opening and deleting a temporary file in /var/tmp.
Greetings, Piotr
--- a/checkrestart 2008-07-17 21:54:30.885890488 +0200 +++ b/checkrestart 2008-07-18 11:58:36.580890545 +0200 @@ -218,7 +218,7 @@ last = process.descriptors.pop() # Add it to the list of deleted files if the previous descriptor # was DEL or lsof marks it as deleted - if re.compile("DEL").search(last) or re.compile("deleted").search(data): + if re.compile("DEL").search(last) or re.compile("deleted").search(data) or re.compile("\(path inode=[0-9]+\)$").search(data): process.files.append(data) else: # We discard the previous descriptors and drop it