Hi there, this is my first post so be nice =)

I had been using firefox 3 on slack12 since it was released without (m)any problems. Now, suddenly, it can't find the helper app for pdf files (and only pdf files). I have no idea what caused the change.

Here's the problem:
Within firefox, I can use the gui Edit>Prefs>Apps> and add or remove additional apps. It doesn't appear to be possible to change the 'default' per se but firefox seems to remember the last program used. For example, the system default for msword files is kword but firefox opens them automatically in soffice. Great- so I know it's possible...

The 'default' app for pdf files is set to kpdf (as in my gnome config). If i try to open a pdf file from firefox, it suggest kpdf, then gives "..the associated helper application does not exist" error. Changing the system default to gv, firefox now correctly suggests gv as the helper app, but again fails to find it. If I choose 'other' and specify the path it works fine.

If I open the download bar in firefox and double click the offending pdf file, it doesn't open, but if I right click and select 'open,' it does. I assume the first action uses firefox and the second nautilus or whatever.

What's weird is that I don't seem to be able to change anything using Edit>Prefs>Apps>pdf, i.e. although I can specifically add additional programs which are retained in this config list, they are not presented when trying to open a pdf - only the system default is shown.

I started messing about with the mimeTypes.rdf file but it doesn't make any difference. I tried removing it, and editing the file to explicitly specify the path to some (any!) pdf tool... to no avail. But it seems to me that shouldn't be necessary anyway?

I can't figure out why this should only affect one helper definition. It may well be something stupid but I'd appreciate someone pointing it out nonetheless..

Thanks for reading the whole ramble =)

I haven't yet tried out FF3, but I will venture a guess that it has an 'about:config' page built in as do the rest of the Firefoxes.
Try entering about:config into the address bar, and on the produced page, you *might* be able to set up (defaults) paths and executables for helper apps. Be forewarned, there are typically a LOT of options in there, but it does have a search field.
I went through the same procedure with FF2.x with full success, to configure PDF helper app(s) and JAVA locations.

Good luck!

Sasha