User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1 Browser goes to a website that has pdf files. Pdf files are available for reading. Default reader is Adobe Acrobat Pro 9 (not Adobe Reader). Pdf file is properly opened, viewed and saved. Then back button on browser is clicked to back to website. Browser then crashes. Same exact sequence with IE does not crash. Seems to happen only on secure sites. Reproducible: Sometimes Steps to Reproduce: 1. Go to secure site with viewable pdf 2. Open pdf and then save using save page as 3. Click back button, browser crashes. Software should have gone back to website.

read http://developer.mozilla.org/En/How_to_get_a_stacktrace_for_a_bug_report Do you read it inline ? In such a case the plugin may crash and that IE works is unrelated because IE needs an ActiveX plugin and all other browers are using NPAPI plugins.

Following TechNote by Adobe(pointed in meta Bug 336184 Comment #12) is possibly applicable to Adobe Acrobat 9 and/or Adobe Reader 9 too. > http://kb.adobe.com/selfservice/viewContent.do?externalId=328233&sliceId=2 To Anthony Diepenbrock(bug opener): Will procedure described in the TechNote resolve your crash problem?

If this didn't fix it, we'll need a crash report. See http://developer.mozilla.org/En/How_to_get_a_stacktrace_for_a_bug_report

This may be fixed with the new release of Reader/Acrobat 9.1 (without stack traces or crash reports I can't know for sure). If you do install 9.1, please verify that the nppdf32.dll in the plugins folder is upgraded to 9.1; it should be, but we have some reports that sometimes it is not.

Anthony, did updating to Acrobat 9.1 fix the problem for you?

WFM based on comment 4.