firefox sync problem (only android device): I can't choose login-psw from dropdown list when i have more then one login-psw for a single webpage.

Dear firefox team, I run into a problem with filling login-password forms on my android device (Huawei ascend g600, android v 4.0...). If a web page is coupled with more then one login-passward pair by firefox, then the login form remains empty whatever I do. But if the only login-password pair is saved for a page, it appears immediately once the page has been loaded. This problem takes place on my android device only. On my home PC (win7) everything goes fine: In case of several login-password pairs for a page I can easily choose the one I need, from a dropdown list, after clicking the login subform. Is it a a shortcoming of a mobile version or I just haven't managed to find the answer? RSVP, thank you