Have you received any Reports from people, other than read receipts, that people created themselves? I think that's a very unlikely occurrence. That would be the only scenario in which you would receive a Report from someone, with "Read: " on it, and it isn't a read receipt. I think you're safe in that respect. I mean, if you do receive other reports, they will probably be generated by Outlook, and they wouldn't have "Read: " in their subject--they would have something else, depending on what kind of report it is.
I'm not sure I understand what problem you're having when you say the read receipts aren't moving properly to the specified folder. My first instinct would be to ask if you've set up the rule properly. In an attempt to avoid misunderstanding, I'll go through the whole thing step by step (for Outlook 2000):
1. Go to your Inbox.
2. Click on Organize.
3. Click on the Rules Wizard.
4. Click on New (assuming you haven't set this rule up yet; if you have, click on Modify, or delete your old one and start over by clicking New).
5. Select "Check messages when they arrive" and hit Next.
6. Click to check the box next to "with specific words in the subject"
7. Click on specific words where it appears in the Rule description, and then type "Read: " with a colon and a space, but without quotation marks, where it says "Add." Hit Add, then OK.
8. Click to check the box next to "uses the form name form"
9. Click on form name where it appears in the Rule description, and then click in the drop-down menu at the top of the resulting dialog box, and choose Application Forms. Scroll down to where it says Report; select Report and click on Add. Then hit Close.
10. Hit Next.
11. In the "What do you want to do with this message?" listbox, select the check box next to "move it to the specified folder".
12. Click on specified where it appears in the Rule description, and then select the destination folder to which you want your read receipts automatically moved. Hit OK.
13. Click on Next.
14. Hit Next again (you don't need any exceptions).
15. Type a name for this rule.
16. Make sure both check boxes are selected: "Run this rule now on messages already in 'Inbox'" and "Turn on this rule".
17. Click on Finish.
18. In the "Apply rules in the following order" listbox, select the rule you just created, and then click on the Move Up button until it's at the top. If you want all the read receipts to be automatically moved, then it should be safe to have this rule at the very top.
19. Click on OK.
You're done! All of your read receipts should be moving automatically to your destination folder. The key in your case may be to make sure that this rule is processed first, above all others. Do you have any code in the NewMail event that handles incoming messages? If you don't know what I mean, then you probably don't. If you do have code there, then you need to take it into consideration vis-a-vis your new rule in your Inbox.
Is the destination folder another regular folder within your mailbox, such as a subfolder under your Inbox? If it's anything else--a PST, or a folder in a different mailbox, then problems can occur.
If you have followed all these steps and the rule still doesn't seem to work, please post your symptoms in more detail, and post more details about your software setup (Outlook version, whether you're on a network, connected to Exchange, etc.)
Christopher