Windscreen wipers on VCalibra

[divlong]

The intermittent wipe on my Calibra works, errr, intermittently. Sometimes it doesn't seem to work at all, sometimes it seems fine and sometimes I just get a long pause between wipes and it will do a double wipe.

Is this likely to be something simple (and cheap) to fix?

Also, is it possibly to fit a proper variable wipe as the gap between wipes is a bit too long.

Cheers

Duncan