response code: 400

Blackberry 8700c.
Software installs and runs w/o any errors.
But I get:
'A network error has occurred, probably due to poor reception. HTTP response code: 400 ' while trying to sign in.

Receptions is good, host name has http or https prefix. Host name is reachable from device (plain HTML client works via HTML browser just fine)

Any ideas?

hmmm, Anything in the debug log or in your server logs?

all we have found is:

These are from the mailbox.log file

2007-12-19 09:35:24,482 INFO [ImapSSLServer-89357] [] ProtocolHandler - Exception occurred while handling connection
javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
at com.sun.net.ssl.internal.ssl.InputRecord.handleUnk nownRecord(InputRecord.java:523)
at com.sun.net.ssl.internal.ssl.InputRecord.read(Inpu tRecord.java:355)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRec ord(SSLSocketImpl.java:789)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.perform InitialHandshake(SSLSocketImpl.java:1096)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRe cord(SSLSocketImpl.java:623)
at com.sun.net.ssl.internal.ssl.AppOutputStream.write (AppOutputStream.java:59)
at java.io.BufferedOutputStream.flushBuffer(BufferedO utputStream.java:65)
at java.io.BufferedOutputStream.flush(BufferedOutputS tream.java:123)
at com.zimbra.cs.imap.ImapHandler.sendLine(ImapHandle r.java:2097)
at com.zimbra.cs.imap.ImapHandler.sendResponse(ImapHa ndler.java:2087)
at com.zimbra.cs.imap.ImapHandler.sendUntagged(ImapHa ndler.java:2077)
at com.zimbra.cs.imap.ImapHandler.setupConnection(Ima pHandler.java:183)
at com.zimbra.cs.tcpserver.ProtocolHandler.run(Protoc olHandler.java:186)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Wo rker.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)

We don't see any 400 errors in anything we've looked at so far. What logs we have to examine in particular? Are there any log in on device itself (created by J2ME your client)?