{pre} tags not working

Greetings, I'm working on a locally installed XWiki, using the 0.9.840 release. I've got a couple problems with Wiki syntax that I need assistance with. First, I want to use the {pre} tags around some text, but XWiki seems to be stripping the tags out. For example: this {pre}*text*{/pre} sample ...will show up with "text" in bold type. When I edit the page, the {pre} tags are gone. this *text* sample Our XWiki installation is very new. {pre} worked for a while, but then stopped working, making me question whether there was a (system?) change made a some point that caused {pre} to stop working. I've also got problems where Wiki {table} will turn to HTML the next time the page is edited. Is this related to, or somehow a clue to the {pre} problem? Thanks in advance for any assistance, John