Uhm... there is no plugins dir in my ~/.thunderbird
Or do you mean the empty dir in the TB dir? As in:

leon@leon-fyg:/usr/local/thunderbird/chrome/toolkit/content/mozapps/plugins$

try to create ~/.thunderbird/plugins and put in it the java plugin

Didn't work.
I read somewhere that TB doesn't support plugins at all.

I read somewhere that TB doesn't support plugins at all.
This is silly, much web sites use macromedia flash content, so it mean alll TB users can't see flash sites ?

Removing ~/.mozilla/plugins/libjavaplugin_oji.so 'solves' the problem.
I'm not sure what you mean, as Thunderbird is a stand alone mail/newsgroup reader, not a web browser. Anyway, here's where I found it (old bug report) https://bugzilla.mozilla.org/show_bug.cgi?id=221695

Lol, my bad I didn't know really what Thunderbird was.

I saw this bugzilla entry as well. I have the same problem with thunderbird 0.8 on both a SuSE 9.1 box and a redhat 9 box. I upgraded java on the redhat 9 box to java 1.5 and the problem went away. Haven't upgraded java on my SuSE 9.1 box because there are two separate java (java2 and java2-jre) packages and I don't know how to upgrade them short of removing both packages and installing java 1.5 from scratch.

Now, I may have done something else on the redhat 9 box to make the problem go away, so the java upgrade may not solve the problem. However, it is worth trying.

Anand

Sorry for replying to my own message. I upgraded Java on my SuSE 9.1 Pro box from Java 1.4.2 to Java 1.5 and the thunderbird mail compose crash problem went away. Specifically, I downloaded Sun's JDK1.5.0 package (the linux bin package and NOT the rpm.bin package). I then installed jdk1.5.0 as /usr/lib/SunJava-1.5.0 and changed the symbolic link /usr/lib/java to point to /usr/lib/SunJava-1.5.0. After this, just to be safe, I changed the libjavaplugin_oji.so symbolic link in /usr/lib/browser-plugins to point to /usr/lib/SunJava-1.5.0/jre/plugin/i386/ns7/libjavaplugin_oji.so. I also changed the .mozilla/plugins/libjavaplugin_oji.so to point to /usr/lib/SunJava-1.5.0/jre/plugin/i386/ns7/libjavaplugin_oji.so. After doing this, I fired up thunderbird and was able to compose a message and send it without thunderbird crashing. Have not tested this more carefully and have not tested the new java plugin on firefox. [For firefox, it may be necessary to change the libjavaplugin_oji.so symbolic links in either/both /opt/mozilla/lib/plugins and /opt/MozillaFirefox/lib/plugins.]

If SuSE 9.2 Pro which is slated to ship in Nov contains SunJava-1.5.0 and not SunJava-1.4.2, then this problem should automatically resolve itself with a distro upgrade. However, I don't know if SuSE 9.2 contains SunJava-1.5.0. I suspect it does but do not know for sure.

Anand