I asked this question on stackoverflow, and I've been suggested to repost it here.
I have a problem accessing my site (on https) with IEMobile 9 (WP 7.5).
It says it's got problem with the certificate, as if it wasn't valid. Everything works on any other browser or platform I tested (android (several phones and a galaxy tab with stock browser, firefox, opera, dolphin), iOS (iphone and ipad with safari and chrome), an old nokia with symbian, windows 7, linux and mac).
To try to solve this I saved the certificate (.cer) on the server and accessed it from the phone browser. It always complained except when I accessed it through the server IP (192.168.xx.xx). At that point it (said it) installed correctly the certificate. If then I try to access the index.html still using the IP all works fine and it doesn't complain about the certificate. If, though, I try to access the index using the actual URL (blah.myblah.com), it complains again about the certificate, as if it wasn't installed!
It isn't a problem of DNS, cause that's up and serving the right ip, and the phone is correctly setup to use it.
The certificate is signed by geotrust/rapidssl for *.myblah.com.
Edit: added info
:~$ openssl s_client -connect blah.myblah.com:443
CONNECTED(00000003)
depth=0 /serialNumber=az2FuQJsYguGU37CPKkH8XRt2J6HBYYr/OU=GT51835720/OU=See www.rapidssl.com/resources/cps (c)12/OU=Domain Control Validated - RapidSSL(R)/CN=*.myblah.com
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 /serialNumber=az2FuQJsYguGU37CPKkH8XRt2J6HBYYr/OU=GT51835720/OU=See www.rapidssl.com/resources/cps (c)12/OU=Domain Control Validated - RapidSSL(R)/CN=*.myblah.com
verify error:num=27:certificate not trusted
verify return:1
depth=0 /serialNumber=az2FuQJsYguGU37CPKkH8XRt2J6HBYYr/OU=GT51835720/OU=See www.rapidssl.com/resources/cps (c)12/OU=Domain Control Validated - RapidSSL(R)/CN=*.myblah.com
verify error:num=21:unable to verify the first certificate
verify return:1
---
Certificate chain
0 s:/serialNumber=az2FuQJsYguGU37CPKkH8XRt2J6HBYYr/OU=GT51835720/OU=See www.rapidssl.com/resources/cps (c)12/OU=Domain Control Validated - RapidSSL(R)/CN=*.myblah.com
i:/C=US/O=GeoTrust, Inc./CN=RapidSSL CA
---
Server certificate
-----BEGIN CERTIFICATE-----
<certificate>
-----END CERTIFICATE-----
subject=/serialNumber=az2FuQJsYguGU37CPKkH8XRt2J6HBYYr/OU=GT51835720/OU=See www.rapidssl.com/resources/cps (c)12/OU=Domain Control Validated - RapidSSL(R)/CN=*.myblah.com
issuer=/C=US/O=GeoTrust, Inc./CN=RapidSSL CA
---
No client certificate CA names sent
---
SSL handshake has read 1897 bytes and written 319 bytes
---
New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1
Cipher : DHE-RSA-AES256-SHA
Session-ID: <session-ID>
Session-ID-ctx:
Master-Key: <Master-Key>
Key-Arg : None
Start Time: 1354176967
Timeout : 300 (sec)
Verify return code: 21 (unable to verify the first certificate)
---
openssl s_client -showcerts -connect blah.myblah.com:443
and post the results?