[Typo3-UG Australia] Breaking DB

[Bernie]

G'day People !

New to Typo3 - I d/l it a few weeks back and have taken a cursory sift 
through much of the documentation and played with the example site 
several times. I'm VERY impressed ! Powerful system and definately the 
sort of thing I'm looking for !

However - I keep hitting a fundamental snag in Typo. I keep breaking the 
Database ! :( (4th time now)

No specific reason, and certainly nothing techincal like manually coding 
elements. But I get errors like "can't find GIF" and "Cache not found" 
or more specifically I get this one:

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL 
result resource in C:\apache\htdocs\VRgrafix\t3lib\class.t3lib_db.php on 
line 689

resulting in a borken site. This often necessitates I reinstall Typo - 
as no matter how much I try to "fix" the DB with the supplied tools - it 
inevitably does nothing :(( I've obviously checked the line in question 
- but means little to me (I'm no programmer) The more common error I 
seem to get is the cache (Why does it need a cache of the pages?) does 
not seem to accurately mirror the "real" pages. Requiring mysql manual 
fixing of the table.

I've hardly put Typo3 into a "real world" scenario yet - but amongst my 
menial playing with templates and changing colours seems to break the 
system so easily - should one wonder what it would be like with a live 
website ?? Is this just me - am I doing something fundamentally wrong or 
should one treat Typo with a gentle, change one thing at a time and 
backup religiously approach ?

Many thanks in advance,

Bernie den Hertog
VRgrafix
www.vrgrafix.com.au