Help! Dates cause corruption of files!

I am getting a lot of trouble with corruption in HTML files
which is something to do with dates.



Here is an example of corrupted source code:



Although the areas under solar collectors are shaded, they
still receive quite a lot of light, quite sufficient for growing
plants and without the damaging effect of direct tropica%26lt;!--
#BeginDate format:IS1 --%26gt;2007-10-26%26lt;!-- #EndDate --%26gt;rwise
be useless for any kind of cultivation could become very
productive.



This is typical: the code %26lt;!-- #BeginDate format:IS1
--%26gt;2007-10-26%26lt;!-- #EndDate --%26gt; has been put into the
middle of some text and has wiped out part of the text. It is
entirely unclear to me why this should be happening. But it happens
a lot and is proving to be a major headache.



The only place that I use that date code is in the footer of
a template that is used for most pages. Normally it means that the
date when each page was last updated can be seen and normally this
works correctly. But the same code is also inserted randomly into
text in pages throughout my website.



Can anyone help, please?! This is becoming a major problem.



With thanks,



Gerry