problems w.bloggar

Hi everybody,
I tested w.bloggar. For me it?′s a very good tool because at home I have just a dial up connection. And I think it has a lot of very good features.
Unfortunately I get a lot of erros while posting. For example:
“For some strange yet very annoying reason, the entry couldn?′t be edited.”
Maybe there are some settings in WordPress which are not compatible with w.bloggar. Another reason might be encoding or charset.
I want to post to my blog in German so I have some of the extended chars.
Can anybody give my some hints to avoid these errors?
oerdec//