Hi Vince_Wonk,
Greetings from another member in Jakarta as well. I am currently located at Jakarta Barat.
Let me try to answer your questions.
1. It is true that there are many IBM mouse counterfeits currently running around the market. This happens not only in Indonesia. Hongkong, Singapore and Thailand has those counterfeits as well.
How to differentiate?
- Price.. Heck..the original cost me S$35. The IBM's mousy mouse cost around S$7 only.
- Box. Can you find any box on your counterfit IBM? no...an original IBM mouse comes with a nifty hard box to ensure safety during transport.
Pic of box:

Pic when opening the box:

- Cord. The original one has thicker and much more solid cable. The counterfeit one seems to be wiggly all the time.
- Color of the roller ball. IBM original is RED illumination while the counterfeit one illuminates blue.
http://www.lautanmas.com/images/campur/mouse_1.jpg
- Label on the bottom. IBM original one is actually a sticker. While on the counterfeit one...you can find some printed directly on the material of the mouse..and find are sticker as well.
- Getting technical? Try to open each casing and you can tell which is IBM and which is 'AiBiEm'
Why do I know these things? We have bought over 16 mice for the last 3 years. Yes.I have done my researched and was tempted to buy the cheap IBM mouse. Well, after I have learned my lesson, I never looked back. Now, all of our mice are IBM's original..
Why not use other?
Firstly, I have found out that the travelmouse from IBM has the right feeling and size for all of us here using IBM. It's just the right mouse...
Secondly, the cruising mode for travelmouse is about 30% faster than non-IBM mouse. Heck..I dont know why this can be since an 800dpi mouse from all brands (Logitech included) wont do the same speed as this little travelmouse.
Thus, all our employees using a thinkpad always use the original IBM mouse so far. We also keep stock of this mouse for extra machines coming up for our little company.
The first mouse was bought back at Aug 2004 and it still works now on daily basis. By the way, I have one mouse that does double-clicking all the time. That was the only faulty one out of the 16 mice we have.
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Why spend 15 minutes replying to this thread? I have researched around for the same issue you are dealing with.
Bellow is the picture of my old original IBM Mouse. When IBM was still and IBM (not Lenovo) the logo was IBM. For the last 1.5 year, all the mice are getting the "THINKPAD LOGO"
OLD MOUSE ORIGINAL IBM (prior 2006):
NEW MOUSE ORIGINAL THINKPAD (2006-2007 comes from Lenovo):
http://www.lautanmas.com/images/campur/mouse_1.jpg
By the way, you can find a very limited store in Indonesia who carry the original IBM mouse. If they do, they will carry a pretty nifty price of Rp.495,000
Now..here comes the fun part
If you'd like I have a spare one that I can pass to you as my regards to another thinkpads.com forum user.
Brand NEW! LENOVO seal is still intact in the box..never been opened.
E-mail me for details: mipra @ earthlink.net
Hope that helps..
MOD EDIT: Two overlimit pictures modified to links.