Below are some good examples of how to handle older browsers when using gzip and expiration dates on your files. Older browsers sometimes have difficulties with gzip so you may want to use this code as well.
# Enable ETag
FileETag MTime Size
# Set expiration header
ExpiresActive on
ExpiresDefault “access plus 1 year”
ExpiresByType image/gif A2592000
ExpiresByType image/png A2592000
ExpiresByType image/jpeg A2592000
ExpiresByType text/css A2592000
# Compress some text file types
AddOutputFilterByType DEFLATE text/html text/plain text/css text/xml application/x-javascript text/javascript application/javascript
# Deactivate compression for buggy browsers
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0 no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
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