My Handset is not so powerful, do you have any performance tips for me?
Do not enable compression unless you transfer files that would profit from compression and your network traffic is really valuable. Large text files for example are good to compress. Any audio or video files usually are not. The cost of the uncompressed protocol overhead is insignificant.

If you use SSH's private key files for identification, make sure the key size is not too large. A large key size drastically increases the time it takes for you to open a connection. I would suggest not to use keys of more than 1024 bit.

It is often a good idea to make use of proxy servers. Even the use of an SSH gate with its heavy use of encryption can increase your performance by keeping up a continuous connection. Many WebDAV and FTP servers tend to drop connections very early and you have to re-connect often. A proxy may help, try it.

I don't know my BlackBerry OS version, what files do I need to download?

From the Home screen enter "Options" section. Now enter "About" section (possibly named "Info"). The number you are looking for is on the third line. The device from this screenshot is running version 4.5. I marked it with a read rectangle. In this case you would use the files that are marked with the tag For BlackBerry OS 4.3.0+

I forgot my password but it still asks me for it even after a fresh installation?! / The user data is not removed when the application is reinstalled?!
To make sure that all userdata is removed you need to remove the Pader-Sync application first. Then reinstall it. If you install the software without removing it first the userdata will remain.

If this fails on Nokia devices you may have to do it the Nokia way and send a magic SMS in-between:

"The RMS[userdata] is not deleted if the MIDlet is replaced by another MIDlet that has the same name. The RMS[userdata] is always deleted if the MIDlet is removed from the device. The easiest solution to delete an existing RMS[userdata] is to ask the end user to remove the current MIDlet and then send an SMS and download the second MIDlet to the device. "