Since TiddlyWiki is 'self-contained' you can, of course, continue to use the older revision. However, the version of TiddlyWiki you are using was from the *beta* release process and there have been several significant changes since then.
The problem with not upgrading is that people will answer your questions using the *current* TiddlyWiki methodolgies and syntax and, as you have discovered, these solutions may be 100% compatible with your old beta revision (e.g., the tag for stylesheets is now Capitalized, and the classname prefix was changed from "tw" to "tc")
One VERY important advantage of upgrading to the current full release version is that, unlike the beta revisions, Jeremy has committed to ensuring that all future revisions to TiddlyWiki will maintain backward-compatibility.
enjoy,
-e
Eric Shulman
TiddlyTools / ELS Design Studios
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