This was caused by coding errors in some of the add-ons and adjustments we had experimented with. We did a fresh install on a spare dommain and after dumping some old and redundant data and extras we recreated the extras we had added. When it was fine we then restored to this site.

Some valuable lessons were learned.

First was the need to check in all browsers more often, whilst Firefox has a reasonable market share Internet explorer is still the main one but it is important to check as many platforms as we can. We now have the main browsers on both 64bit Visa and 32bit Windows XP Pc's to test.

A further lesson was concerning mambo and the add-ons available. Ours was a very early mambo that has been played with and added to. Recently Mambo has the facility to upgrade easier and add-ons are better.

The issue is with sites not kept upto date and where old add-ons are causing problems. In doing the upgrade we were able to use only the areas we wanted to keep and lose the redundant items some of which had not fully restored. Therefore we were able to import ALL our data to effectively a clean install.

For most users with recent versions, especially 4.6.x and above as long as you do the upgrades then there should be no problems for the rest we can now at least fresh install and repair these errors without losing any data.