Bibtex's inproceedings gives me an error. 

entries:

@inproceedings{elgamal:84,
Author = {T. ElGamal},
Crossref = {crypto84},
Pages = {10--18},
Title = {{A Public Key Cryptosystem and a Signature Scheme Based on Discrete Logarithms}}}
@proceedings{crypto84,
Booktitle = {{Proceedings of Crypto '84}},
Editor = {G. R. Blakley and D. Chaum},
Publisher = pub-springer,
Series = j-lncs,
Title = {{Advances in Cryptology}},
Volume = {196},
Year = {1985}}
These worked in the past and should be ok.

The error is:
<to be read again> 
                  \pbd: 
\bibgetvart #1->\csname pbd:#1\endcsname 
                                        \plussix 
\bibalternative ... \??pv \@@currentalternative #1
                                                 \endcsname 
\dotypesetapublication ...ative {\bibgetvart {#1}}
                                                 \removeunwantedspaces \egr...
\9>>3 #1,->\dobibdata {#1}
                         \syst_helpers_do_process_comma_item 
\syst_helpers_do_process_comma_list ...rgument #1,
                                                 ]\relax \global \advance \...
...
l.5 ...elijke klaartekst\footnotecite[elgamal:84].

Version of ConTeXt:
ConTeXt  ver: 2012.07.20 00:58 MKIV  fmt: 2012.7.22  int: english/english

Version of bibtex according to the log
This is BibTeX, Version 0.99d (TeX Live 2012)

\footnotecite puts an bibentry in a footnote, other citations pose no problem, just inproceedings.

Hans van der Meer