When trying to install any version of AdobeReader 9 on Vista 32bit, SP1+Updates, I have the same phenomenon:
1. AdobeReader setup launches and extracts all data successfully
2. a "Microsoft ODBC Setup" installer is launched
3. typical install runs through without any errors
4. Setup finishes successfully, I select "OK"
5. there is no point 5, Adobe Reader installer does not continue but quits silently.
I guess the result from the ODBC setup (why do I need that anyway?) is interpreted wrongly by Adobe's (custom?) installer and thinks something went wrong.
I have previously used AdobeReader 8.0.2 without problems, deinstalled successfully and cleanly, then tried both the German and English version of AdobeReader, both through the website and directly by FTP (using the link supplied in an other thread by Paul).
In my case this was caused by the presence of a MS ODBC setup.exe file programfiles\SAP\FrontEnd\SAPgui\FILC\odbc. This file was in PATH and thus triggered, I renamed the file temporarily and the install works. Probably goes for any file named setup.exe in PATH.