Disclaimer: I am not a FirePass administrator; only an end-user and have no other relationship with F5. There may be better methods to address this issue; please comment if you know of one.
Preliminaries: Although the F5 FirePass SSL VPN product supports Linux, as best as I can tell, that support is somewhat limited: My understanding is that they officially claim support for 32-bit installs only, and they do not appear to track new distribution releases particularly aggressively. F5 has also been somewhat slow in supporting new browser versions: They announced support for Firefox 3 on October 6, 2008, nearly four months after its release and with only two months to go before Firefox 2 was end-of-lifed. For Firefox 3.6 support, a comment on the post linked above states that you need to request a special hot fix from F5 (which my site has not applied). There is no Google Chrome support that I am aware of.
Further, F5’s automated client installation tools have unfortunately never worked for me on Linux, even when the architecture and browser are in their support matrix. The manual download instruction links are also broken on the FirePass install I connect to.
Solution: Install a dedicated, 32-bit version of Firefox in a supported version; create a single-purpose Firefox profile for VPN use. Add the FirePass client to that browser and the operating system.