Acrobat PDF reader for Internet Explorer may be unloading/unabling custom plugin

Question

Hi,
My question is basically to understand what is happening in this situation so that I can find where is the problem and how to solve it.
We have used Acrobat 6.0 SDK to develop our custom plugin. This plugin is basically wrapper to few basic tools  (note, stamp, text ) etc.. provided by Acrobat 6.0 SDK. We have also developed PDFViewer.dll to view PDF document within Internet Explorer. So when user load document within our website this PDFViewer loaded with the custom plugin and user can use those tools.
We are installing this plugin under <Acrobat X>/Plug_ins/<Company Name>/MyPlugin.API.
In our web site we are giving list of documents and when user click on a document it will load the PDFViewer and custom plugin. We are loading Acrobat.exe in advance so that we can load quickly.  Now the problem happens when user open any other PDF in different tab or instance of Internet explorer. ?How?
Consider in a internet explorer user logged in our web site and then he/she can see let's say 10 documents. 1.pdf, 2.pdf, 3.pdf, etc...
Now when user select document 1.pdf we are loading that PDF in the IE within our PDFViewer with custom plugin. (Here I have seen that behind the scene Acrobat.exe is loaded in the processed using task manager)/  If at this time if user opens another instance of Internet explorer or another tab and open a PDF document it opens PDF in the standard Adobe Reader PDF viewer for Internet Explorer resides at (C:\Program Files\Common Files\Adobe\Acrobat\ActiveX).
If at this time user goes back to our site and tried to work on 1.pdf our custom plugin works fine BUT if user opens any other document (let's say 2.pdf) the plug in stops working basically looks like it is not loaded.
This issue only happens if user opens a document in another internet tab or explorer instance and open PDF which resulted in to open Acrobat Activex for internet explorer. If user opens a PDF document out side of internet explorer it is not creating any problem because at that time ActiveX does not loaded.
So my guess is something is going on when ActiveX for PDF is get loaded into Internet Explorer.
I want to know more what is happening and why it is happening. Due to this behavior our web site users can't use any other web site which opens PDF documents because then they have to log off and log back in our web site.
Please we need immediate help.
I am open to provide more details with screen captures.
Thanks,
Twinkle

Answer 1

Hi,
Thanks.
So I want to make sure this is because with Acrobat 9 - the new way to deal with PDF's?  Because as per my knowledge it was working fine with Acrobat 8.
Moreover, if I am understanding correctly and I have tested too, the order is important here, right? If I will load PDF in IE first and then I will work on my web site it is not creating problem but if I will launch my web site first and then open PDF within IE in different tab it is creating problem because they are using same interface and when AcroPDF instantiating overriding and failed to load plug_in
Here I have seen that both Acrobat.exe and AcroPDF.dll is using same Acrobat.dll pointing to same memory addresses and that's why problem is happening.
IT would be great if you can provide any other way to "hook" adobe because the bottom line I have to use AcroExch.App from SDK.
One last question, I have seen that if I am opening a PDF in Internet Explorer in a different tab (not in my web app) while pressing SHIFT key and the move to my web site and load different document it is working fine, so the question is what different is happening when we open PDF in IE with pressing SHIFT key and without pressing SHIFT key. IS AcroPDF.dll behaves differently while opening PDF with SHIFT key pressed?
Thanks for all your help.
Twinkle