illegal xhtml attributes?

Vendor: IBM
Processor version: Lotus I think.  (bsf.jar, bsfengines.jar, lotusxsl.jar,
xalan.jar, xerces.jar)

Hi,

I'm perplexed.  I have xml code which includes some xhtml code.  When I try
to perform an xslt transformation on it, I get the following warning:

XSL Warning: Illegal attribute name: alt

the xml code looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<xbutton>
  <image height="22" width="45" alt="Reset">images/gray.gif</image>
  <clear/>
</xbutton>

What's strange is that there is no adverse effect on my output, and the
error message tends to be intermittent.  For example, this code does not
generate the same warning:
<?xml version="1.0" encoding="UTF-8"?>
<xbutton>
  <image height="22" width="45" alt="Reset">images/gray.gif</image>
</xbutton>

There is no "alt" anywhere in my xsl file.  I also get this other warning
from time to time when transforming xhtml code:
XSL Warning: Illegal attribute name: class

So, I am wondering...
A) why this is happening?
B) are there any negative effects?
C) how can i avoid this error short of not using the "alt" and "class" html
attributes?

Thank you,
Dominic Tocci

PS - (I apologize if this message was sent twice)


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