(Sent quickly. Please excuse brevity.)

On 03/10/2010, at 11:41 PM, Philipp Stephani <[log in to unmask]> wrote:

> Am 03.10.2010 um 14:02 schrieb David Perry:
> 
>> If I omit the option, or use 'xetex' in place of 'hypertex' or use the driverfallback option, I get:
>> 
>> ! Undefined control sequence.
>> \str_if_eq_p:nn #1#2->\tex_ifnum:D \pdf_strcmp:D
>>                                                {\etex_unexpanded:D {#1}}{\...
>> l.479 ...p:w  \cs_set_nopar:cpn  \cs_set_nopar:Npn
>> 
>> I fixed the missing commas but that made no difference.
> 
> Looks like an expl3 problem: \pdf_strcmp:D is pdfTeX's \pdfstrcmp, which might be nonexistent or available under a different name in XeTeX. This *might* get fixed by updating expl3; otherwise write to the LaTeX list ([log in to unmask], I've put it on CC).

I think I fixed this coincidentally earlier today. The update will roll out in a timely fashion.  

You should be able to work around this problem by writing

    \let\pdfstrcmp\strcmp

early in your preamble. If I've got this right, that is — I'm not in front of the code right now.  

Hope this helps,
W